Cita APA (7th ed.)

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

Cita Chicago (17th ed.)

Pennings, Paul, Hans Keman, i Jan Kleinnijenhuis. Doing Research in Political Science: An Introduction to Comparative Methods and Statistics. London: Sage, 1999.

Cita MLA (9th ed.)

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