Cita APA (7th ed.)

Müller, D. H., & Fritz, J. (1976). Portale (o.A.). Prisma-Verlag.

Cita Chicago (17th ed.)

Müller, Dr. Hans, i Joachim Fritz. Portale. o.A. Leipzig: Prisma-Verlag, 1976.

Cita MLA (8th ed.)

Müller, Dr. Hans, i Joachim Fritz. Portale. o.A. Prisma-Verlag, 1976.