Fragment of the Vajrakilaya Root Tantra
Fragment of the Root Tantra of Vajrakilaya, (Tib. Phurpa Tsadum, Wyl. phur pa rtsa dum). Sakya Pandita found a small part of the original Vajrakilaya Root Tantra (Skt. Vajrakīlayamūlatantrakhaṇḍa; Wyl. rdo rje phur pa rtsa ba’i rgyud kyi dum bu) in Samye Monastery. Notes were written on it that suggested the text had belonged to Guru Rinpoche. It resolved many questions that had arisen about the authenticity of various Vajrakilaya practices. Sakya Pandita translated it into Tibetan, and the text is included in the Nyingma Kama, with a commentary by Jamgön Kongtrul Lodrö Thaye. Jamyang Khyentse Chökyi Lodrö wrote a short text explaining how to best read the text. 
'Fragment of the Vajrakīla Root Tantra', translated by Martin J. Boord, in A Bolt of Lightning From The Blue (Berlin: Edition Khordong, 2002), pages 79-90.
- Jamgön Kongtrul, Words that Delight the Awesome Ones: A Quintessential Commentary on the Fragment of the Glorious Vajrakīla Root Tantra (dpal rdo rje phur pa rtsa ba'i rgyud kyi dum bu'i 'grel pa snying po bsdus pa dpal chen dgyes pa'i zhal lung)
- Wyl. phur ba rtsa dum rgyud kyi bklags thabs phrin las mchog grub. English translation: Supreme Siddhi Activities, A companion manual for reading the Fragment of the Vajrakilaya Root Tantra, translated by Gyurme Avertin, 2018.