APA (7th ed.) Citation

Yard, R. S. (1937). The book of the national parks. Scribner.

Chicago Style (17th ed.) Citation

Yard, Robert Sterling. The Book of the National Parks. New York: Scribner, 1937.

MLA (9th ed.) Citation

Yard, Robert Sterling. The Book of the National Parks. Scribner, 1937.

Warning: These citations may not always be 100% accurate.