Cita APA (7th ed.)

Campbell, J. A. (1988). The distribucion, variation, natural history, and relationships of Porthidium barbouri (Viperidae). Instituto de Ecología, A.C.

Cita Chicago (17th ed.)

Campbell, Jonathan A. The Distribucion, Variation, Natural History, and Relationships of Porthidium Barbouri (Viperidae). Instituto de Ecología, A.C, 1988.

Cita MLA (9th ed.)

Campbell, Jonathan A. The Distribucion, Variation, Natural History, and Relationships of Porthidium Barbouri (Viperidae). Instituto de Ecología, A.C, 1988.