APA

Field W. D., Herrera J., . (1977). Pierid butterflies of the genera Hypsochila ureta, Phulia herrich - schõffer, Infraphulia field, Pierphulia field, and Piercolias staudinger. Nueva York: Smithsonian Institution Press.

Chicago

Field William D, Herrera José, . 1977. Pierid butterflies of the genera Hypsochila ureta, Phulia herrich - schõffer, Infraphulia field, Pierphulia field, and Piercolias staudinger. Nueva York: Smithsonian Institution Press.

Harvard

Field W. D., Herrera J., . (1977). Pierid butterflies of the genera Hypsochila ureta, Phulia herrich - schõffer, Infraphulia field, Pierphulia field, and Piercolias staudinger. Nueva York: Smithsonian Institution Press.

MLA

Field William D, Herrera José, . Pierid butterflies of the genera Hypsochila ureta, Phulia herrich - schõffer, Infraphulia field, Pierphulia field, and Piercolias staudinger. Nueva York: Smithsonian Institution Press. 1977.