Jabarkan Encyclopædia Britannica: Pentarchy dari Pentarki

Merriam-Webster's Encyclopedia of World Religions: An A–Z Guide to the World's Religions, by Wendy Doniger, M. Webster (Merriam–Webster, 1999 ISBN 0-87779-044-2, ISBN 978-0-87779-044-0): Patriarch

Catholic Encyclopedia: Patriarch and Patriarchate