APA (7th ed.) Citation

Sachs, A. (2006). The Humboldt current: Nineteenth-century exploration and the roots of American environmentalism. Viking.

Chicago Style (17th ed.) Citation

Sachs, Aaron. The Humboldt Current: Nineteenth-century Exploration and the Roots of American Environmentalism. New York: Viking, 2006.

MLA (9th ed.) Citation

Sachs, Aaron. The Humboldt Current: Nineteenth-century Exploration and the Roots of American Environmentalism. Viking, 2006.