Schaeffer, Dreaming, pp. 76-77. Here there is mention of his commentary on Saraha's People Dohā, although no such work seems to be known.
Bibliography:
Cakrasaṃvarasahajatattvāloka (Dpal 'khor lo sdom pa'i lhan cig skyes pa'i de kho na nyid snang ba). Tôh. no. 1504. Dergé Tanjur, vol. ZHA, folios 271r.4-272r.3. Tr. by Dīpaṅkararakṣita and Mar pa Chos kyi dbang phyug.
KCDS, p. 82. Sanskrit palmleaf manuscript now belonging to the Potala. Tibetan version of the title given as Dpal nag po rdo rjes mdzad pa'i do hā mdzod kyi 'grel pa. Note gives author as Dpal Dpag med rdo rje.
Drepung Catalog, p. 1066: Slob dpon nag po spyod pas mdzad pa'i do ha mdzod kyi bshad pa slob dpon dpag med rdo rjes mdzad pa'o.