Contains the keyword Qualitative Study
How Do Free/Open Source Developers Pick Their Tools? A Delphi Study of the Debian Project [Internet]. 38th International Conference on Software Engineering (ICSE 2016). 2016. https://www.researchgate.net/publication/291312269_How_Do_FreeOpen_Source_Developers_Pick_Their_Tools_A_Delphi_Study_of_the_Debian_Project .
Understanding Sustained Participation in Open Source Software Projects. J. Manage. Inf. Syst. [Internet]. Armonk, NY, USA: M. E. Sharpe, Inc.; 2009;25:9–50. http://portal.acm.org/citation.cfm?id=1554441.1554443 .