APA (7th ed.) Citation

Tilden, F. (1968). The national parks (1st rev. ed.). Knopf.

Chicago Style (17th ed.) Citation

Tilden, Freeman. The National Parks. 1st rev. ed. New York: Knopf, 1968.

MLA (9th ed.) Citation

Tilden, Freeman. The National Parks. 1st rev. ed. Knopf, 1968.