APA (7th ed.) Citation

Clay, H. (1918). Economics, an introduction for the general reader. Macmillan.

Chicago Style (17th ed.) Citation

Clay, Henry. Economics, an Introduction for the General Reader. New York: Macmillan, 1918.

MLA (9th ed.) Citation

Clay, Henry. Economics, an Introduction for the General Reader. Macmillan, 1918.