Cita APA (7a ed.)

Heffner, R. D. (1956). A documentary History of the united states. The New American Library.

Cita Chicago Style (17a ed.)

Heffner, Richard D. A Documentary History of the United States. New York: The New American Library, 1956.

Cita MLA (9a ed.)

Heffner, Richard D. A Documentary History of the United States. The New American Library, 1956.