Cita APA

Hartman, G., & Hartman, G. (1945). These United States and how they came to be. New York: Macmillan Company.

Citación estilo Chicago

Hartman, Gertrude, y Gertrude Hartman. These United States and How They Came to Be. New York: Macmillan Company, 1945.

Cita MLA

Hartman, Gertrude, y Gertrude Hartman. These United States and How They Came to Be. New York: Macmillan Company, 1945.