Yin, Robert (2008), Case Study Research: Design and Methods (Applied Social Research Methods) Fourth Edition, Sage: Los Angeles.
Pires, Rui P. (2015), Modos de explicação, Sociologia Problemas e Práticas, 78
http://ic.daad.de/accra/download/How_to_write_a_research_proposal.pdf
Olk, Harald (2003) ?How to write a research proposal?
Creswell, JW & Plano Clark, VL (2011), Designing and Conducting Mixed Methods Research, London, Sage
Costa, AF (1986), A pesquisa de terreno em sociologia, em Silva, AS & Pinto, JM (orgs.), Metodologia das Ciências Sociais, Porto, Afrontamento.
Costa, AF et al (2013), Mixed-methods evaluation in complex programmes, Evaluation and Program Planning, 39
Bryman, A (2012), Social Research Methods, Oxford UP
Becker, HS (1998), Tricks of the Trade, The U. Chicago Press, Chicago
Bell, Judith (1997) Como realizar uma projeto de investigação, Gradiva, Lisboa: