Cita APA (7a ed.)

Klopper, A., Genazzani, A. R., & Crosignani, P. G. (1980). The human placenta: Proteins and hormones. Academic Press.

Cita Chicago Style (17a ed.)

Klopper, Arnold, Andrea R. Genazzani, y P. G. Crosignani. The Human Placenta: Proteins and Hormones. London [etc.]: Academic Press, 1980.

Cita MLA (9a ed.)

Klopper, Arnold, et al. The Human Placenta: Proteins and Hormones. Academic Press, 1980.