APA (7th ed.) Citation

Spencer, R. (2014). Did Muhammad exist?: An inquiry into Islam's obscure origins (Paperback ed.). ISI.

Chicago Style (17th ed.) Citation

Spencer, Robert. Did Muhammad Exist?: An Inquiry into Islam's Obscure Origins. Paperback ed. Wilmington: ISI, 2014.

MLA (9th ed.) Citation

Spencer, Robert. Did Muhammad Exist?: An Inquiry into Islam's Obscure Origins. Paperback ed. ISI, 2014.

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