Pennings, P. (2006). Doing research in political science (2nd ed.). Sage.
Chicago-referens (17:e uppl.)Pennings, Paul. Doing Research in Political Science. 2nd ed. London ; Thousand Oaks, Calif: Sage, 2006.
MLA-referens (9:e uppl.)Pennings, Paul. Doing Research in Political Science. 2nd ed. Sage, 2006.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.