APA (7th ed.) Citation

Pennings, Keman, & Kleinnijenhuis. (1999). Doing research in political science: An introduction to comparative methods and statistics. SAGE.

Chicago Style (17th ed.) Citation

Pennings, Keman, and Kleinnijenhuis. Doing Research in Political Science: An Introduction to Comparative Methods and Statistics. London: SAGE, 1999.

MLA (9th ed.) Citation

Pennings, et al. Doing Research in Political Science: An Introduction to Comparative Methods and Statistics. SAGE, 1999.