The Nyingma School of Tibetan Buddhism: Its Fundamentals and History, Two Volumes (Wisdom Advanced Book Blue)
by Bdud-ʼjoms ʼJigs-bral-ye-śes-rdo-rje, Gyurme Dorje
Category: Rñiṅ-ma-pa (Sect)

The most complete and exhaustive reference work on the Nyingma School of Tibetan Buddhism available.