Bahá'í world faith : selected writings of Bahá'u'lláh and 'Abdu'l-bahá. - Bahá'u'lláh, 1817-1892. (OLS)http://pul/name/74010; 'Abdu'l-Bahá, 1844-1921. (OLS)http://pul/name/74011 (Bahá'í- Publishing Trust, 1956)