APA (7th ed.) Citation

Robertson, J. M. (1899). A short history of freethought: Ancient and modern. Sonnenschein.

Chicago Style (17th ed.) Citation

Robertson, John M. A Short History of Freethought: Ancient and Modern. London [u.a.]: Sonnenschein, 1899.

MLA (8th ed.) Citation

Robertson, John M. A Short History of Freethought: Ancient and Modern. Sonnenschein, 1899.

Warning: These citations may not always be 100% accurate.