Cita APA (7th ed.)

Heinroth, O., & Heinroth, K. (1959). The birds. Faber.

Cita Chicago (17th ed.)

Heinroth, Oskar, i Katharina Heinroth. The Birds. London: Faber, 1959.

Cita MLA (8th ed.)

Heinroth, Oskar, i Katharina Heinroth. The Birds. Faber, 1959.