Cita APA (7a ed.)

Meyer-Abich, A., Hentschel, C., Humboldt, A. v., & Hentschel, C. (1969). Alejandro de Humboldt: 1769-1969. Inter Nationes.

Cita Chicago Style (17a ed.)

Meyer-Abich, Adolf, Cedric Hentschel, Alexander von Humboldt, y Cedrid Hentschel. Alejandro De Humboldt: 1769-1969. Bad Godesberg: Inter Nationes, 1969.

Cita MLA (9a ed.)

Meyer-Abich, Adolf, et al. Alejandro De Humboldt: 1769-1969. Inter Nationes, 1969.