Joanna Grela, Mahakala. The Six-Armed Protector Deity in Tibetan Buddhism. [Mahakala. Sześcioręki strażnik w buddyzmie tybetańskim], Wydawnictwo Universitas, Krakow 2005.

Mahakala. The Six-Armed Protector Deity in Tibetan Buddhism is a unique monograph dedicated to one of the most important figures in the tantric pantheon. It provides a cultural context and presents various aspects of the worship of protectors and guardian deities, their complex symbolism and multiple roles. While compiling materials on the subject, the author studied the rich source literature and conducted field research in the Tibetan academic and monastic centres in India where this kind of worship is still active.