Oracles and Demons of Tibet:

Abstract

The book can be useful if you know what you're looking for in terms of iconographic details (maybe with the intention of engaging in creative visualization), or to familiarize with native (pre-Buddhist/Bön) supernatural beings that were incorporated into the Buddhist pantheon, such as various "lords of the soil/genius loci" (sadak) and serpent-spirits (lu/Skt. nága), etc. This massive study (first edition: Mouton, The Hague 1956) is based on the field research Nebesky-Wojkowitz pursued between 1950 and 1953 at Indo-Sikkimese border town of Kalimpong, aided by three clerical informants: Dardo Tulku and Tretong Rinpoche of the Geluk order, and the Nyingmapa Chimé Rigdzin