(1987). The New Encyclopaedia Britannica Volume 22 [Muhammad and the religion of Islam]. The University of Chicago.
Chicago-viite (17. p.)The New Encyclopaedia Britannica Volume 22 [Muhammad and the Religion of Islam]. The University of Chicago, 1987.
MLA-viite (8. p.)The New Encyclopaedia Britannica Volume 22 [Muhammad and the Religion of Islam]. The University of Chicago, 1987.
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