APA (7th ed.) Citation

Spencer, R., & Jansen, J. J. G. (2012). Did Muhammad exist?: An inquiry into Islam's obscure origins. ISI Books.

Chicago Style (17th ed.) Citation

Spencer, Robert, and Johannes J. G. Jansen. Did Muhammad Exist?: An Inquiry into Islam's Obscure Origins. Wilmington, Delaware: ISI Books, 2012.

MLA (9th ed.) Citation

Spencer, Robert, and Johannes J. G. Jansen. Did Muhammad Exist?: An Inquiry into Islam's Obscure Origins. ISI Books, 2012.