Cita APA (7th ed.)
Hegner, R. (1942). The Century biological series. Appleton-Century.
Cita Chicago (17th ed.)
Hegner, Robert. The Century Biological Series. New York, London: Appleton-Century, 1942.
Cita MLA (9th ed.)
Hegner, Robert. The Century Biological Series. Appleton-Century, 1942.
Atenció: Aquestes cites poden no estar 100% correctes.