contained in the collected works of ཕག་མོ་གྲུ་པ་རྡོ་རྗེ་རྒྱལ་པོ། (1110–1170); acc. to ངག་དབང་བསམ་གཏན། (b. 1949) it was "perhaps authored by one of Phag mo gru pa's disciples" Stearns 2001 (p. 29)