Feagin, J. R., Orum, A. M., & Sjoberg, G. (1991). A Case for the case study. Chapel Hill: University of North Carolina Press.

https://books.google.com/books/about/A_Case_for_the_Case_Study.html?id=7A39B6ZLyJQC

or ILL MSU,M Memorial Library –General Collection HM48 .C37 1991

p. 2 case study is defined as an in-depth

Multi-faceted investigation, using qualitative research methods, of a single social phenomenon.
use of several data sources.

Some case studies have made use of both qualitative and quantitative methods.

Comparative framework.

The social phenomenon can vary: it can be an organization, it can be a role, or role-occupants.

p. 3Quantitative methods: standardized set of q/s