Jacoby, Susan (2004). Freethinkers: a history of American secularism. New York: Metropolitan Books. ISBN 0-8050-7442-2
Royle, Edward (1974). Victorian Infidels: the origins of the British Secularist Movement, 1791-1866. Manchester: Manchester University Press. ISBN 0-7190-0557-4Online version
Royle, Edward (1980). Radicals, Secularists and Republicans: popular freethought in Britain, 1866-1915. Manchester: Manchester University Press. ISBN 0-7190-0783-6
Tribe, David (1967). 100 Years of Freethought. London: Elek Books.
