APA (7th ed.) Citation

Robertson, J. M. (1906). A short history of freethought: Ancient and modern (2d. ed.). G.P. Putnam's.

Chicago Style (17th ed.) Citation

Robertson, J. M. A Short History of Freethought: Ancient and Modern. 2d. ed. New York: G.P. Putnam's, 1906.

MLA (9th ed.) Citation

Robertson, J. M. A Short History of Freethought: Ancient and Modern. 2d. ed. G.P. Putnam's, 1906.