Cita APA (7th ed.)
Spencer, R., & Jansen, J. J. G. (2012). Did Muhammad exist?: An inquiry into Islam's obscure origins. ISI Books.
Cita Chicago (17th ed.)
Spencer, Robert, i Johannes J. G. Jansen. Did Muhammad Exist?: An Inquiry into Islam's Obscure Origins. Wilmington, Delaware: ISI Books, 2012.
Cita MLA (9th ed.)
Spencer, Robert, i Johannes J. G. Jansen. Did Muhammad Exist?: An Inquiry into Islam's Obscure Origins. ISI Books, 2012.
Atenció: Aquestes cites poden no estar 100% correctes.