Tolong jelaskan mengenai 坤元觀 dari Xi Wangmu

Transcendence and Divine Passion: The Queen Mother of the West in Medieval China, oleh Dr. Suzanne Elizabeth Cahill, Stanford University Press, ISBN 0-8047-2584-5

Chinese Mythology: An Introduction, Anne Birrell, 1999, Penerbit: Johns Hopkins University Press, ISBN 0-8018-6183-7