Mani Kabum (Wyl. ma Ni bka' 'bum) - a collection of teachings and practices focused on Avalokiteshvara, attributed to King Songtsen Gampo and revealed as a terma by three different masters: the siddha Ngödrup, Nyangrel Nyima Özer, and Shakya Ö.
Bryan Phillips, “Consummation and Compassion in Medieval Tibet: The Mani bka’-‘bum chen-mo of Guru Chos-kyi dbang-phyug” (unpublished PhD thesis)
Matthew Kapstein, 'Remarks on the Maṇi bKa'-'bum and the Cult of Āvalokiteśvara in Tibet', in Tibetan Buddhism: Reason and Revelation edited by Steven D Goodman and Ronald M. Davidson, SUNY, 1992
Matthew Kapstein, 'The Royal Way of Supreme Compassion', in Religions of Tibet in Practice, edited by Donald S. Lopez Jr., Princeton University Press, 1997