Hanegraaff، Wouter J. (2013). "What is Western esotericism?". Western Esotericism: A Guide for the Perplexed. Guides for the Perplexed. London: Bloomsbury Academic. ص. 3. ISBN:978-1-4411-8897-7. اطلع عليه بتاريخ 2018-11-11. The adjective 'esoteric' first appeared in the second century CE [...].
