I. Benbasat, D. K. Goldstein, and M. Mead, The case research strategy in studies of information systems, MIS quarterly, pp.369-386, 1987.

J. Colazo and Y. Fang, Impact of license choice on open source software development activity, Journal of the American Society for Information Science and Technology, vol.60, issue.5, pp.997-1011, 2009.

J. W. Creswell, V. L. Clark, M. L. Gutmann, and W. E. Hanson, Advanced mixed methods research designs. Handbook of mixed methods in social and behavioral research, vol.209, p.240, 2003.

K. Crowston and J. Howison, The social structure of open source software development teams, First Monday, vol.10, issue.2, 2005.

E. Davini, E. Faggioni, and D. Tartari, Open Source Software in Public Administration. A real example OSS for e-Government observatories, First Intl Conf on Open Source Systems, pp.119-124, 2005.

S. Dueñas, V. Cosentino, G. Robles, and J. M. Gonzalez-barahona, Perceval: Software project data at your will, 40th ICSE Companion Proc. pp, pp.1-4, 2018.

R. T. Fielding, Shared leadership in the Apache project, Communications of the ACM, vol.42, issue.4, pp.42-43, 1999.

D. M. German, The evolution of the GNOME Project, Proceedings of the 2nd Workshop on Open Source Software Engineering, pp.20-24, 2002.

J. M. Gonzalez-barahona, D. Izquierdo-cortazar, S. Maffulli, and G. Robles, Understanding how companies interact with free software communities, IEEE Software, vol.30, issue.5, pp.38-45, 2013.

L. Guijarro, Interoperability frameworks and enterprise architectures in egovernment initiatives in europe and the united states, Government Information Quarterly, vol.24, issue.1, pp.89-101, 2007.

A. Hautamäki and K. Oksanen, Digital platforms for restructuring the public sector. In: Collaborative Value Co-creation in the Platform Economy, pp.91-108, 2018.

V. Hollmann, H. Lee, H. Zo, and A. P. Ciganek, Examining success factors of open source software repositories: the case of OSOR.eu portal, Intl Journal of Business Information Systems, vol.14, issue.1, pp.1-20, 2013.

V. Hollmann and H. Zo, OSOR.eu: an open source sharing system for e-Government solutions in the EU, Convergence and Hybrid Information Technology, 2008. ICCIT'08. Third Intl Conf on, vol.2, pp.992-996, 2008.

P. Huysmans, K. Ven, and J. Verelst, Reasons for the non-adoption of OpenOffice.org in a data-intensive public administration, First Monday, vol.13, issue.10, p.10, 2008.

. Inera, En kunskaps PM om nationell interoperabilitet Hur befintliga lsningar i Sverige idag frhller sig till X-Road, 2018.

A. Kalja, The X-Road project. A project to modernize Estonia's national databases, Baltic IT&T review, vol.24, pp.47-48, 2002.

A. Kalja, K. Kindel, R. Kivi, and T. Robal, eGovernment services: How to develop them, how to manage them? In: Management of Engineering and Technology, Portland Intl Center for, pp.2795-2798, 2007.

T. Kalvet, The Estonian information society developments since the 1990s, PRAXIS, 2007.

B. Klievink, A. Zuiderwijk, and M. Janssen, Interconnecting governments, businesses and citizens-a comparison of two digital infrastructures, Intl Conf on Electronic Government, pp.84-95, 2014.
URL : https://hal.archives-ouvertes.fr/hal-01401727

T. Kotka, C. Vargas, and K. Korjus, Estonian e-residency: Redefining the nation-state in the digital era, Working Paper Series, vol.3, pp.1-16, 2015.

G. L. Kovács, S. Drozdik, G. Succi, and P. Zuliani, Open source software for the public administration, Proceedings of the 6th Intl Workshop on Computer Science and Information Technologies, 2004.

A. Van-loon and D. Toshkov, Adopting open source software in public administration: The importance of boundary spanners and political commitment, Government Information Quarterly, vol.32, issue.2, pp.207-215, 2015.

B. Lundell, e-Governance in public sector ICT procurement: what is shaping practice in Sweden?, European Journal of ePractice, vol.12, issue.4, pp.66-78, 2011.

B. Lundell and F. Van-der-linden, Open source software as open innovation: experiences from the medical domain, Managing open innovation technologies, pp.3-16, 2013.

E. Maldonado, The process of introducing FLOSS in the public administration: the case of Venezuela, Journal Association for Inf. Systems, vol.11, issue.11, p.756, 2010.

D. G. Messerschmitt and C. Szyperski, Software ecosystem: understanding an indispensable technology and industry, vol.1, 2005.

A. Mondorf and M. A. Wimmer, Requirements for an architecture framework for paneuropean e-government services, Intl Conf on Electronic Government, pp.135-150, 2016.
URL : https://hal.archives-ouvertes.fr/hal-01636453

T. Nam, Government 3.0 in korea: fad or fashion?, Proceedings of the 7th Intl Conf on Theory and Practice of Electronic Governance, pp.46-55, 2013.

M. M. Nielsen, Governance failure in light of Government 3.0: Foundations for building next generation eGovernment maturity models. In: Government 3.0-Next Generation Government Technology Infrastructure and Services, pp.63-109, 2017.

K. Paide, I. Pappel, H. Vainsalu, and D. Draheim, On the systematic exploitation of the Estonian data exchange layer X-Road for strengthening public-private partnerships, Proceedings of the 11th Intl Conf on Theory and Practice of Electronic Governance, pp.34-41, 2018.

G. Robles and J. M. González-barahona, A comprehensive study of software forks: Dates, reasons and outcomes, pp.1-14, 2012.
URL : https://hal.archives-ouvertes.fr/hal-01519079

G. Robles, J. M. Gonzalez-barahona, and I. Herraiz, Evolution of the core team of developers in libre software projects, 2009.

B. Rossi, B. Russo, and G. Succi, A study on the introduction of Open Source Software in the Public Administration, IFIP Intl Conf on Open Source Systems, pp.165-171, 2006.

M. Shaikh, Negotiating open source software adoption in the UK public sector, Government Information Quarterly, vol.33, issue.1, pp.115-132, 2016.

M. Tiik and P. Ross, Patient opportunities in the Estonian electronic health record system, Stud Health Technol Inform, vol.156, pp.171-178, 2010.

A. G. Tsahkna, E-voting: lessons from Estonia, European View, vol.12, issue.1, pp.59-66, 2013.

G. Walsham, Doing interpretive research, European Journal of Information Systems, vol.15, issue.3, pp.320-330, 2006.

J. Yli-huumo, T. Päivärinta, J. Rinne, and K. Smolander, Suomi.fi -Towards Government 3.0 with a national service platform, Intl Conf on Electronic Government, pp.3-14, 2018.
URL : https://hal.archives-ouvertes.fr/hal-01961533