APA (7th ed.) Citation

Spencer, H. (1907). The study of sociology (Library ed., with a postscript.). Williams and Norgate.

Chicago Style (17th ed.) Citation

Spencer, Herbert. The Study of Sociology. Library ed., with a postscript. London: Williams and Norgate, 1907.

MLA (9th ed.) Citation

Spencer, Herbert. The Study of Sociology. Library ed., with a postscript. Williams and Norgate, 1907.