[Zürcher 1959/2007] Zürcher, Erik. The Buddhist Conquest of China: The Spread and Adaptation of Buddhism in Early Medieval China. Third Edition. Leiden: Brill, 1959 (2007 reprint).
— 312-314
Zürcher argues that the Xumi siyu jing 須彌四域經 is one of a series of “apocryphal” texts to extend the theory that Laozi, Confucius and sometimes Yan Hui and mythical Chinese Emperors were "Buddhist Saints". This theory, Zürcher suggests, was a response to the Daoist huahu 化胡 theory which claimed that the Buddha was in fact Laozi. This text is now lost, but, according to Zürcher, it is extensively quoted in Buddhist literature from the sixth and seventh centuries.