Pieck, W. (1948). Clara Zetkin. Dietz.
Cita Chicago (17th ed.)Pieck, Wilhelm. Clara Zetkin. Berlin: Dietz, 1948.
Cita MLA (8th ed.)Pieck, Wilhelm. Clara Zetkin. Dietz, 1948.
Atenció: Aquestes cites poden no estar 100% correctes.
Cita APA (7th ed.)