APA

Cornell University, . (1991). Living bird. Ithaca, (Nueva York): Cornell Laboratory of Ornithology.

Chicago

Cornell University, . 1991. Living bird. Ithaca, (Nueva York): Cornell Laboratory of Ornithology.

Harvard

Cornell University, . (1991). Living bird. Ithaca, (Nueva York): Cornell Laboratory of Ornithology.

MLA

Cornell University, . Living bird. Ithaca, (Nueva York): Cornell Laboratory of Ornithology. 1991.