Concepts and method in social science : the tradition of Giovanni Sartori
David Collier, John Gerring, editor
Routledge, 2009
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Scholz, Roland W.
Embedded case study methods : integrating quantitative and qualitative knowledge
Sage, 2002
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Strategies of qualitative inquiry
Norman K. Denzin, editor; Yvonna S. Lincoln, editor
Sage Publications, 2003
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Creswell, John W.
Research design : qualitative, quantitative, approaches
Sage, 1994
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Neuman, Lawrence W.
Basics of social research: qualitative and quantitative
Pearson New International edition, 2014
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