Yousif, Ahmad (2000-04-01). "Islam, Minorities and Religious Freedom: A Challenge to Modern Theory of Pluralism". Journal of Muslim Minority Affairs. 20 (1): 35. doi:10.1080/13602000050008889. ISSN1360-2004.
jstor.org
Peters & De Vries (1976), Apostasy in Islam, Die Welt des Islams, Vol. 17, Issue 1/4, pp 15 (footnote 38)
Yousif, Ahmad (2000-04-01). "Islam, Minorities and Religious Freedom: A Challenge to Modern Theory of Pluralism". Journal of Muslim Minority Affairs. 20 (1): 35. doi:10.1080/13602000050008889. ISSN1360-2004.