APA

Spence W., . (1933). Tracts on political economy. New York: Priv. print.

Chicago

Spence William, . 1933. Tracts on political economy. New York: Priv. print.

Harvard

Spence W., . (1933). Tracts on political economy. New York: Priv. print.

MLA

Spence William, . Tracts on political economy. New York: Priv. print. 1933.