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Handbuch der empirischen Sozialforschung
König, René,
Methods in social research
Goode, William Josiah, (1952)
Social surveys for social planners
Gardner, Godfrey, (1978)
Introduction to social research : quantitative and qualitative approaches
Punch, Keith F., (1998)
Survey research : the basics
Punch, Keith F., (2003)
Developing effective research proposals
Punch, Keith F., (2006)