APA (7th ed.) Citation

Opp, K. (1990). Postmaterialism, Collective Action, and Political Protest. American journal of political science, 34(1), 212-235.

Chicago Style (17th ed.) Citation

Opp, Karl-Dieter. "Postmaterialism, Collective Action, and Political Protest." American Journal of Political Science 34, no. 1 (1990): 212-235.

MLA (9th ed.) Citation

Opp, Karl-Dieter. "Postmaterialism, Collective Action, and Political Protest." American Journal of Political Science, vol. 34, no. 1, 1990, pp. 212-235.