Cita APA (7a ed.)

Gerngross, G., & Puchta, H. (1999). The Tree of Life. Longman.

Cita Chicago Style (17a ed.)

Gerngross, Günter, y Herbert Puchta. The Tree of Life. Edinburgh: Longman, 1999.

Cita MLA (9a ed.)

Gerngross, Günter, y Herbert Puchta. The Tree of Life. Longman, 1999.