A2A, 2017 A2A . (2017). Italian energy market overview. 2015 & 2016. Market analysis & price forecasting.

Adams and Schvaneveldt, 1991 Adams, G. , & Schvaneveldt, J. (1991). Understanding research methods (2nd ed.). New York, NY: Longman.

AEEGI, 2017 AEEGI . (2017, March 31). Relazione annuale sullo stato dei servizi e sull'attivita' svolta . Retrieved from https://www.arera.it/allegati/relaz_ann/17/RAVolumeI_2017.pdf. Accessed on July 19, 2018.

AIDA data, 2018 AIDA data (2018). AIDA database. Bureau Van Dyck.

Al Zefeiti and Mohamad, 2015 Al Zefeiti, S. M. B. , & Mohamad, N. A. (2015). Methodological considerations in studying transformational leadership and its outcomes. International Journal of Engineering Business Management, 7(1), 1–11.

ARERA, 2017 ARERA . (2017). Documento per la consultazione 663/2017/R/EEL. Retrieved from https://www.arera.it/allegati/docs/17/663-17.pdf. Accessed on July 6, 2018.

ARERA, 2018 ARERA . (2018, February 20). Che cosa è l'Autorità di Regolazione per Energia Reti e Ambiente. Retrieved from https://www.arera.it/it/che_cosa/presentazione.htm. Accessed on July 7, 2018.

AU, 2018 AU . (2018). Chi siamo. Retrieved from http://www.acquirenteunico.it/societa. Accessed on July 7, 2018.

Bahari, 2010 Bahari, S. F. (2010). Qualitative versus quantitative research strategies: Contrasting epistemological and ontological assumptions. Journal Teknologi, 52, 17–28.

Bernardini et al., 2017 Bernardini, E. , Di Giampaolo, J. , Faiella, I. , & Poli, R. (2017, November). Gli investimenti nelle utilities del settore elettrico: Implicazioni del carbon risk . Numero 410. Questioni di Economia e Finanza. Occasional papers. Banca d'Italia, Rome.

Bhaskar, 1979 Bhaskar, R. (1979). The possibility of naturalism. Atlantic Highlands, NJ: Humanities Press.

Bhaskar, 1989 Bhaskar, R. (1989). Reclaiming reality: A critical introduction to contemporary philosophy. London: Verso.

Blumberg et al., 2005 Blumberg, B. , Cooper, R. , & Schindler, S. (2005). Business research methods. Maidenhead: McGraw-Hill.

British Embassy Tokyo, 2016 British Embassy Tokyo . (2016). UK energy innovation the history and current status of the UK's electricity and gas markets. Tokyo: Carbon Trust.

Bryman, 2012 Bryman, A. (2012). Social research methods (5th ed.). Oxford: Oxford University Press.

Bryman and Bell, 2011 Bryman, A. , & Bell, E. (2011). Business research methods (3rd ed.). Oxford: Oxford University Press.

Capece et al., 2010 Capece, G. , Cricelli, L. , Di Pillo, F. , & Levialdi, N. (2010). A cluster analysis study based on profitability and financial indicators in the Italian gas retail market. Energy Policy, 38, 3394–3402.

Capece et al., 2013 Capece, G. , Di Pillo, F. , & Levialdi, N. (2013). Measuring and comparing the performances of energy retail companies. International Journal of Energy Sector Management, 7(4), 491–515.

Cavallaro, 2018 Cavallaro, D. (2018, April 30). Le energie rinnovabili in Italia: Stato dell'arte e prospettive. Infobuild energia. Retrieved from http://www.infobuildenergia.it/approfondimenti/energie-rinnovabili-italia-prospettive-fotovoltaico-eolico-393.html. Accessed on July 7, 2018.

CEER, 2013 CEER . (2013, April 16). Status review on the transposition of unbundling requirements for DSOs and closed distribution system operators . C12-UR-47-03. Retrieved from https://www.ceer.eu/documents/104400/-/-/f1bf5c46-a772-0190-064f-cc586c444319. Accessed on July 1, 2019.

CEER, 2016 CEER . (2016, April 1). Status review on the implementation of transmission system operators' unbundling provisions of the 3rd energy package . CEER Status Review, Ref: C15-LTF-43-04. Retrieved from https://www.ceer.eu/documents/104400/3731907/C15-LTF-43-04_TSO-Unbundling_Status_Review-28-Apr-2016.pdf/a6a22f89-3202-4f8b-f9ed-adf705185c33?version=1.0. Accessed on July 1, 2019.

CEER, 2017 CEER . (2017, November 21). Retail markets monitoring report . CEER Report, Ref: C17-MMR-83-02. Retrieved from https://www.ceer.eu/documents/104400/-/-/56216063-66c8-0469-7aa0-9f321b196f9f. Accessed on July 2, 2019.

CEER, 2019 CEER . (2019, June 14). Implementation of TSO and DSO unbundling provisions – Update and clean energy package outlook . CEER Status Review, Ref: C18-LAC-02-08. Retrieved from https://www.ceer.eu/documents/104400/-/-/f69775aa-613c-78a5-4d96-8fd57e6b77d4. Accessed on July 1, 2019.

Charmaz, 1996 Charmaz, K. (1996). The search for meanings: Grounded theory. In J. A. Smith , A. Harre' , & L. Van Langenhove (Eds.), Rethinking methods in psychology. London: SAGE Publications.

Chauve et al., 2009 Chauve, P. , Godfried, M. , Kovács, K. , Langus, G. , Nagy, K. , & Siebert, S. (2009). The E.ON electricity cases: An antitrust decision with structural remedies. Competition Policy Newsletter, 1, 51–54.

Collis and Hussey, 2009 Collis, J. , & Hussey, R. (2009). Business research: A practical guide for undergraduate and postgraduate students (3rd ed.). Basingstoke: Palgrave Macmillan.

Consulente Energia, 2018 Consulente Energia . (2018). La vendita dell'energia con i “contratti bilaterali”. Retrieved from http://www.consulente-energia.com/vendita-energia-con-contratti-bilaterali-sul-mercato-otc-piattaforma-pce.html. Accessed on July 6, 2018.

Crowther and Lancaster, 2008 Crowther, D. , & Lancaster, G. (2008). Research methods: A concise introduction to research in management and business consultancy (2nd ed.). Oxford: Elsevier Butterworth-Heinemann.

Daft, 1985 Daft, R. L. (1985). Why I recommended that your manuscript be rejected and what you can do about it. In L. L. Cummings & P. J. Frost (Eds.), Publishing in the organizational sciences. Homewood, IL: Richard D. Irwin.

Dale et al., 1988 Dale, A. , Arber, S. , & Proctor, M. (1988). Doing secondary analysis. London: Unwin Hyman.

Dayanandan and Donker, 2011 Dayanandan, A. , & Donker, H. (2011). Oil prices and accounting profits of oil and gas companies. International Review of Financial Analysis, 20, 252–257.

Delmas et al., 2007 Delmas, M. A. , Russo, M. V. Y. , & Montes-Sancho, M. J. (2007). Deregulation and environmental differentiation in the electric utility industry. Strategic Management Journal, 28, 189–209.

Denzin and Lincoln, 2005 Denzin, N. K. , & Lincoln, Y. S. (Eds.). (2005). The Sage handbook of qualitative research (3rd ed.). Thousand Oaks, CA: SAGE Publications.

Dobson, 2002 Dobson, P. (2002). Critical realism and information systems research: Why bother with philosophy? Information Research, 7(2). Retrieved from http://informationr.net/ir/7-2/paper124.html. Accessed on August 27, 2018.

Dominelli, 2013 Dominelli, C. (2013). Borsa del gas in rampa di lancio. Il Sole 24 Ore, August 31. Retrieved from http://www.ilsole24ore.com/art/impresa-e-territori/2013-08-31/borsa-rampa-lancio-084632.shtml?uuid=AbXDn0RI&refresh_ce=1. Accessed on July 6, 2018.

E-gazette, 2015 E-gazette . (2015). Gas. Il mercato italiano si apre alle borse estere del metano. E-gazette, Milano, Lun, September 21. Retrieved from http://www.e-gazette.it/sezione/energia/gas-mercato-italiano-si-apre-borse-estere-metano. Accessed on July 6, 2018.

Easterby-Smith et al., 2002 Easterby-Smith, M. , Thorpe, R. , & Lowe, A. (2002). Management research an introduction. Thousand Oaks, CA: SAGE Publications.

Ehlers, 2009 Ehlers, E. M. (2009). Electricity and gas supply network unbundling in Germany, Great Britain and The Netherlands and the law of the European Union: A comparison. Antwerp, Oxford and Portland, OR: Intersentia.

EU, 2011 EU . (2011). Annex 2, EU Third package – Transposition note – Great Britain, directive – Gas Directive (2009/73/EC). Retrieved from https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/48157/2574-eu-third-package-trans-note-directive-1.pdf. Accessed on June 30, 2019.

Eurostat data, 2018 Eurostat data . (2018). EUROSTAT database.

EU, 2019 EU . (2019). Clean energy for all Europeans package – Legislative process. Retrieved from https://ec.europa.eu/energy/en/topics/energy-strategy-and-energy-union/clean-energy-all-europeans. Accessed on June 30, 2019.

Faff and Brailsford, 1999 Faff, R. , & Brailsford, T. J. (1999). “Oil price risk and the Australian stock market”. Journal of Energy, Finance and Development, 4(1), 69–87.

Flick, 2011 Flick, U. (2011). Introducing research methodology: A beginner's guide to doing a research project. London: SAGE Publications.

Gill and Johnson, 2002 Gill, J. , & Johnson, P. (2002). Research methods for managers (3rd ed.). London: SAGE Publications.

Glaser, 1978 Glaser, B. (1978). Advances in the methodology of grounded theory: Theoretical sensitivity. Mill Valley, CA: Sociology Press.

Glaser and Strauss, 1967 Glaser, B. , & Strauss, A. (1967). The discovery of grounded theory. Chicago, IL: Aldine.

Glowaci Law Firm, 2019 Glowaci Law Firm . (2019). The EU Energy Package – Regulatory chronicle. Retrieved from https://www.emissions-euets.com/third-energy-package. Accessed on August 15, 2019.

GME, 2017 GME . (2017). Bilancio d'esercizio 2017. Retrieved from http://www.mercatoelettrico.org/En/MenuBiblioteca/documenti/20180607BilancioGME2017.pdf. Accessed on July 7, 2018.

GME, 2018a GME . (2018a). Il mercato elettrico. Retrieved from http://www.mercatoelettrico.org/It/Mercati/MercatoElettrico/IlMercatoElettrico.aspx. Accessed on July 6, 2018.

GME, 2018b GME . (2018b). Il mercato del gas. Retrieved from http://www.mercatoelettrico.org/It/Mercati/MGAS/MGas.aspx. Accessed on July 6, 2018.

GME, 2018c GME . (2018c). Mercati elettrici. Come partecipare. Retrieved from http://www.mercatoelettrico.org/En/Mercati/MercatoElettrico/ComePartecipare.aspx. Accessed on July 7, 2018.

GME, 2018d GME . (2018d). Mercati gas. Come partecipare. Retrieved from http://www.mercatoelettrico.org/En/Mercati/MGas/ComePartecipareMGas.aspx. Accessed on July 7, 2018.

GME, 2018e GME . (2018e). Profilo aziendale. Retrieved from http://www.mercatoelettrico.org/It/GME/Info/ProfiloAziendale.aspx. Accessed on July 7, 2018.

Goddard and Melville, 2004 Goddard, W. , & Melville, S. (2004). Research methodology: An introduction (2nd ed.). Oxford: Blackwell Publishing.

GSE, 2018 GSE . (2018). Le attività. Retrieved from https://www.gse.it/chi-siamo/attivit%C3%A0. Accessed on July 7, 2018.

Guba and Lincoln, 1994 Guba, E. G. , & Lincoln, Y. S. (1994). Competing paradigms in qualitative research. In N. K. Denzin & Y. S. Lincoln (Eds), Handbook of qualitative research. Thousand Oaks, CA: SAGE Publications.

Hakim, 1982 Hakim, C. (1982). Secondary analysis in social research. London: Allen & Unwin.

Hakim, 2000 Hakim, C. (2000). Research design: Successful designs for social and economic research (2nd ed.). London: Routledge.

Harre and Madden, 1975 Harre, R. , & Madden, E.R. (1975). Causal Powers. A Theory of Natural Necessity. Lanham: Rowman & Littlefield Publishing Group.

Heddenhausen, 2007 Heddenhausen, M. (2007). Privatizations in Europe's liberalised electricity markets – The cases of the United Kingdom, Sweden, Germany and France. Berlin: Research Unit Eu Integration German Institute for International and Security Affairs.

Henwood and Pidgeon, 1992 Henwood, K. , & Pidgeon, N. (1992). Beyond the qualitative paradigm: A framework for introducing diversity within qualitative psychology. Journal of Community & Applied Social Psychology, 4(4), 225–238.

House, 1991 House, E. R. (1991). Realism in research. Educational Researcher. American Educational Research Association, 20(6), 2–9.

IEA, 2001 IEA . (2001). Competition in electricity markets. In Energy market reform. Paris: OECD Publishing. doi:10.1787/9789264192768-en.

Iovino, 2012 Iovino, F. (2012). Le scelte delle politiche di marketing delle imprese energetiche. Management delle utilities, 4.

Iovino, 2014 Iovino, F. (2014). L'internet marketing nelle imprese energetiche: Il caso di un'impresa elettrica romana. Mercati & Competitività, (3), 141–161. doi:10.3280/MC2014-003008.

Iovino, 2015 Iovino, F. (2015). Relationship marketing by energy companies. Review of International Comparative Management, 16(5), 558–573.

Iovino and Migliaccio, 2016 Iovino, F. , & Migliaccio, G. (2016). E-marketing by energy companies. In 9th annual conference of the Euromed Academy of Business, “innovation, entrepreneurship and digital ecosystems”, 14–16 September 2016, Warsaw, Poland, Book of Conference Proceedings (pp. 1036–1048). Euromed Press, Demetris Vrontis, Yaakov Weber, Evangelos Tsoukatos (Eds), Cyprus GR.

Iovino and Migliaccio, 2019a Iovino, F. , & Migliaccio, G. (2019a). Energy companies and global economic crisis 2008–2014: Financial dynamics. Some considerations from Italian context. International Journal of Business and Globalisation, 22(4), 541–554.

Iovino and Migliaccio, 2019b Iovino, F. , & Migliaccio, G. (2019b). Energy companies and global economic crisis 2008–2014: Financial dynamics. Some considerations from Italian context. International Journal of Business and Globalisation, (4), 141–161.

Iovino and Migliaccio, in press Iovino, F. , & Migliaccio, G. (in press). Mobile marketing and strategy by energy companies. International Journal of Public Sector Performance Management.

Istat, 2016 ISTAT . (2016). Gross product supply side. Retrieved from dati.istat.it/?lang=en. Accessed on October 5, 2018.

Istat, 2017 ISTAT . (2017). Italy in figures 2016. Rome: ISTAT. Retrieved from https://www.istat.it/it/files//2017/06/Italy_in_figures_16.pdf. Accessed on October 5, 2018.

Jamasb and Pollitt, 2005 Jamasb, T. , & Pollitt, M. (2005). Electricity market reform in the European Union: Review of progress toward liberalization & integration. Energy, 26, 11–41.

Jamasb and Pollitt, 2006 Jamasb, T. , & Pollitt, M. (2006). Electricity market liberalisation and integration in the European Union. CESifo DICE Report – Journal for Institutional Comparisons, 4(2), 16–23.

Jamasb et al., 2008 Jamasb, T. , Pollitt, M. , & Triebs, T. (2008). Productivity and efficiency of US gas transmission companies: A European regulatory perspective. Energy Policy, 36, 3398–3412.

Johnson and Clark, 2006 Johnson, P. , & Clark, M. (2006). Business and management research methodologies. London: SAGE Publications.

Kang et al., 2017 Kang, W. , Perez de Gracia, F. , & Ratti, R.A. (2017). “Oil price shocks, policy uncertainty, and stock returns of oil and gas corporations”. Journal of International Money and Finance, 70(C), 344–359.

Kerlinger, 1973 Kerlinger, F. N. (1973). Foundations of behavioural research. Techniques in business and economics. Boston, MA: McGraw Hill Hirwn.

Kothary, 2004 Kothary, C. R. (2004). Research methodology. Methods and techniques. New Delhi: New Age International Pvt. Ltd.

Krishnaswami and Satyaprasad, 2010 Krishnaswami, O. R. , & Satyaprasad, B. G. (2010). Business research methods. Mumbai, India: Himalaya Publishing House.

Laing, 1967 Laing, R. D. (1967). The politics of experience and the birds of paradise. Harmondsworth: Penguin Books.

Legislative decree 18 giugno, 2007 Legislative decree 18 giugno 2007, n. 73. Misure urgenti per l'attuazione di disposizioni comunitarie in materia di liberalizzazione dei mercati dell'energia. Retrieved from http://www.normattiva.it/uri-res/N2Ls?urn:nir:stato:decreto.legge:2007;73. Accessed on July 19, 2018.

Liberti et al., 2013 Liberti, L. A. , Carillo, A. , & Sannino, G. (2013). Wave energy resource assessment in the Mediterranean, the Italian perspective. Renewable Energy, 50, 938–949.

Longo, 2017 Longo, L. (2017). Energia, Italia aumenta la produzione ma siamo ancora (troppo) dipendenti. Linkiesta, October 13. Retrieved from www.linkiesta.it/it/article/2017/10/13/energia-italia-aumenta-la-produzione-ma-siamo-ancora-troppo-dipendenti/35794/. Accessed on July 19, 2018.

McGrath and Brinberg, 1983 McGrath, J. E. , & Brinberg, D. (1983). External validity and the research process: A comment on the Calder/Lynch dialogue. Journal of Consumer Research, 10(1), 115–124.

Merriam, 1988 Merriam, S. B. (1988). Case study research in education: A qualitative approach. San Francisco, CA: Jossey-Bass.

Migliaccio and Iovino, 2018 Migliaccio, G. , & Iovino, F. (2018). Reshaping the energy markets: The Italian case. International Journal of Business and Social Science, 9(1), 61–70.

Ministery of Economic Development, 2018a Ministery of Economic Development . (2018a). Gas naturale. Produzione. Retrieved from http://www.sviluppoeconomico.gov.it/index.php/it/energia/gas-naturale-e-petrolio/gas-naturale/produzione. Accessed on July 7, 2018.

Ministery of Economic Development, 2018b Ministery of Economic Development . (2018b). Gas naturale. Vendita. Retrieved from http://www.sviluppoeconomico.gov.it/index.php/it/component/content/article?id=2019689:gas-naturale-vendita. Accessed on July 6, 2018.

Ministery of Economic Development, 2018c Ministery of Economic Development . (2018c). Produzione di energia elettrica. Retrieved from http://www.sviluppoeconomico.gov.it/index.php/it/energia/energia-elettrica/autorizzazioni-uniche. Accessed on July 7, 2018.

Mirto and Viviano, 2017 Mirto, A. P. M. , & Viviano, C. (Eds.). (2017). Imprenditorialita' nelle regioni italiane. Caratteri strutturali e socio-economici. Rome: ISTAT. Retrieved from https://www4.istat.it/it/files/2018/04/Imprenditorialit%C3%A0-nelle-regioni-italiane.pdf. Accessed on October 5, 2018.

Morales and McKenzie, 2019 Morales, A. , & McKenzie, B. (2019). Spain. In D. L. Schwartz (Ed.), The energy regulation and markets review. London: Law Business Research Ltd.

Murry and Zhu, 2008 Murry, D. , & Zhu, Z. (2008). Asymmetric price responses, market integration and market power: A study of the US natural gas market. Energy Economics, 30(3), 748–765.

Nikogosian and Veith, 2012 Nikogosian, V. , & Veith, T. (2012). The impact of ownership on price-setting in retail energy markets: The German case. Energy Policy, 41, 161–172.

Oliver, 2004 Oliver, R. (2004). Business research methods (2nd ed.). London: Pearson.

Palasthy, 2002 Palasthy, A. (2002). Third party access in the electricity sector: EC competition law and sector-specific regulation. Journal of Energy and Natural Resources Law, 20(1), 1–26.

Partington, 2000 Partington, D. (2000). Building grounded theories of management action. British Journal of Management, 11, 91–102.

Perry, 2002 Perry, C. (2002). Case research in marketing. The Marketing Review, 1(3), 303–323.

Remenyi, 1998 Remenyi, D. (1998). Doing research in business and management: An introduction to process and method. London and Thousand Oaks, CA: SAGE Publications.

Robson, 2002 Robson, C. (2002). Real world research (2nd ed.). Oxford: Blackwell Publishing.

Sackett and Larson, 1990 Sackett, P. R. , & Larson, J. R., Jr. (1990). Research strategies and tactics in industrial and organizational psychology. In M. D. Dunnette & L. M. Hough (Eds.), Handbook of industrial and organizational psychology (pp. 419–489). Palo Alto, CA: Consulting Psychologists Press.

Saunders et al., 2009 Saunders, M. , Lewis, P. , & Thornhill, A. (2009). Research methods for business students (5th ed.). Essex: Pearson Education Limited.

Saunders and Tosey, 2013 Saunders, M. , & Tosey, P. (2013). The layers of research design. Rapport, Winter 2012/2013, pp. 58–59.

Scandura and Willimas, 2000 Scandura, T. A. , & Willimas, E. A. (2000). Research methodology in management: Current practices, trends, and implications for future research. Academy of Management Journal, 43(6), 1248–1264.

Schülke, 2010 Schülke, C. (2010). The EU's major electricity and gas utilities since market liberalization. In Gouvernance Européenne et Géopolitique Del'énergie (Vol. 10). Paris: IFRI.

Serralles, 2006 Serralles, R. J. (2006). Electric energy restructuring in the European Union: Integration, subsidiarity and the challenge of harmonization. Energy Policy, 34, 2542–2551.

Silverman, 2013 Silverman, D. (2013). Doing qualitative research: A practical handbook. London: SAGE Publications.

Snam, 2018 Snam . (2018). Chi siamo. Retrieved from http://www.snam.it/it/chi-siamo/. Accessed on July 7, 2018.

Sobh and Perry, 2006 Sobh, R. , & Perry, C. (2006). Research design and data analysis in realism research. European Journal of Marketing, 40(11/12), 1194–1209.

Staiton-Rogers, 2006 Staiton-Rogers, W. (2006). Logics of inquiry. In S. Potter (Ed.), Doing postgraduate research. Thousand Oaks, CA and London: SAGE Publications.

Strauss, 1987 Strauss, A. L. (1987). Qualitative analysis for social scientists. New York, NY: Cambridge University Press.

Suddaby, 2006 Suddaby, R. (2006). From the editors: What grounded theory is not. Academy of Management Journal, 49(4), 633–642.

Terna, 2017 Terna . (2017). Annual report 2017 integrated report. Retrieved from http://download.terna.it/terna/0000/1042/46.PDF. Accessed on July 10, 2018.

Terna, 2018 Terna . (2018). Terna in breve. Retrieved from http://www.terna.it/it-it/chi-siamo/lenostreattivita.aspx. Accessed on July 7, 2018.

Toniutti, 2011 Toniutti, T. (2011). Referendum, i “Sì” oltre il 95% risultato storico, “Una vittoria di tutti”. La Repubblico, June 13. Retrieved from http://www.repubblica.it/politica/2011/06/13/news/referendum_la_giornata_dei_s_il_quorum_arriva_tra_le_polemiche-17645020/. Accessed on July 7, 2018.

Torriti et al., 2010 Torriti, J. , Hassan, M. G. , & Leach, M. (2010). Demand response experience in Europe: Policies, programmes and implementation. Energy, 35, 1575–1583.

Tsoukas, 1989 Tsoukas, H. (1989). The validity of idiographic research explanations. Academy of Management Review, 24(4), 551–561.

U.S. Energy Information Administration, 2014 U.S. Energy Information Administration . (2014). Retrieved from https://www.indexmundi.com/energy/?country=it&product=oil&graph=production+consumption. Accessed on July 8, 2018.

Vasconcelos, 2004 Vasconcelos, J. (2004). Design and regulation of the EU energy market. In 4th EU/US Energy Regulators' Roundtable Lisboa, May12–13, 2003. Retrieved from https://www.ceer.eu/documents/104400/-/-/b239358a-bf42-7c17-c75a-95ac3e5e97d9. Accessed on July 31, 2019.

Vătavu et al., 2018 Vătavu, S. , Lobont,, O. , Para, I. , & Pelin, A. (2018). Addressing oil price changes through business profitability in oil and gas industry in the United Kingdom. PLoS One, 13(6), 1–22, e0199100. doi:10.1371/journal.pone.0199100. Retrieved from http://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0199100&type=printable. Accessed on July 31, 2018.

Wilson, 2010 Wilson, J. (2010). Essentials of business research: A guide to doing your research project. New York, NY: SAGE Publications.

Yang et al., 2006 Yang, Z. , Wang, X. , & Su, C. (2006). A review of research methodologies in international business. International Business Review, 15(6), 601–617.