Cita APA (7th ed.)

Mußgnug, M., & Quelle, G. (1979). Profil.

Cita Chicago (17th ed.)

Mußgnug, Martin, i Gerhard Quelle. Profil. Stuttgart, 1979.

Cita MLA (8th ed.)

Mußgnug, Martin, i Gerhard Quelle. Profil. 1979.