Ryugen Tanemura, Mṛtasugatiniyojana: A Manual of the Indian Buddhist Tantric Funeral, Newsletter of the NGMCP, no. 4 (May 2007), pp. 2-6, at p. 2, note 1. The codex unicus is preserved in the Tokyo University Library, and there is no known Tibetan translation. It is based on Guhyasamāja, by its own testimony.