Pennings, P., Keman, H., & Kleinnijenhuis, J. (1999). Doing research in political science: An introduction to comparative methods and statistics. Sage.
Chicago-viite (17. p.)Pennings, Paul, Hans Keman, ja Jan Kleinnijenhuis. Doing Research in Political Science: An Introduction to Comparative Methods and Statistics. London: Sage, 1999.
MLA-viite (9. p.)Pennings, Paul, et al. Doing Research in Political Science: An Introduction to Comparative Methods and Statistics. Sage, 1999.
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