1. Beer, R. (1999). The Encyclopedia of Tibetan Symbols and Motifs. Boston: Shambhala Publications.
2. Bhattacharyya, B. (1958). The Indian Buddhist Iconography, Mainly Based on The Sādhanamālā and Cognate Tantric Texts of Rituals. Calcutta: Mukhopadhyay.
3. Blofeld, J. (1992). The Tantric Mysticism of Tibet: A Practical Guide to the Theory, Purpose, and Techniques of Tantric Meditation. USA: Penguin Books.
4. Buswell, R. E. & Lopez, D. E. (2014). The Princeton Dictionary of Buddhism. Princeton: Princeton University Press.
5. Buswell, R. E. (2004). Encyclopedia of Buddhism I-II. Detroit: Thomsen Gale.