APA

Heffner R. D., . (1954). History of The United States. New York: A. Mentor Book.

Chicago

Heffner Richard D, . 1954. History of The United States. New York: A. Mentor Book.

Harvard

Heffner R. D., . (1954). History of The United States. New York: A. Mentor Book.

MLA

Heffner Richard D, . History of The United States. New York: A. Mentor Book. 1954.