APA (7th ed.) Citation

Harding, W. R. (1966). The days of Henry Thoreau. Knopf.

Chicago Style (17th ed.) Citation

Harding, Walter Roy. The Days of Henry Thoreau. New York: Knopf, 1966.

MLA (9th ed.) Citation

Harding, Walter Roy. The Days of Henry Thoreau. Knopf, 1966.