APA
Pirenne H., . (1968). Mohammed and Charlemagne. London: Unwin University Books.
Chicago
Pirenne Henri, . 1968. Mohammed and Charlemagne. London: Unwin University Books.
Harvard
Pirenne H., . (1968). Mohammed and Charlemagne. London: Unwin University Books.
MLA
Pirenne Henri, . Mohammed and Charlemagne. London: Unwin University Books. 1968.
