APA

Essig E. O., . (1926). Insects of western North America. New York: Macmillan.

Chicago

Essig Edward Oliver, . 1926. Insects of western North America. New York: Macmillan.

Harvard

Essig E. O., . (1926). Insects of western North America. New York: Macmillan.

MLA

Essig Edward Oliver, . Insects of western North America. New York: Macmillan. 1926.