APA

Elton G. R., . (19681967). The practice of history. New York: Crowell.

Chicago

Elton G R, . 19681967. The practice of history. New York: Crowell.

Harvard

Elton G. R., . (19681967). The practice of history. New York: Crowell.

MLA

Elton G R, . The practice of history. New York: Crowell. 19681967.