The Four Yakshinis (Tib. Nöjin Shyi)  are female protector deities of Tibet, bound under oath by Guru Padmasambhava. They are:-
Fleshless White Glacier - Dorje Yudrönma
Kharak Khyung Tsün - Dorje Palgyi Yum
Sky Soarer of the Great Treasures - Dorje Lumo
Mari Rabjam - Dorje Drakmo Gyal
- * The notes on Lamrim Yeshe Nyingpo, Entering the Path of Wisdom, by Jamyang Drakpa, as recorded by Jokhyab Rinpoche, from Lamrim Yeshe Nyingpo, Vol. 2, published by Rangjung Yeshe Publications, ISBN 962-7341-33-9, page205. Original source mentioned in the notes is Ratna Linpa’s Tukdrub Yangdü.
- Padmasambhava and Jamgön Kongtrul, Lamrim Yeshe Nyingpo, Vol. 2, published by Rangjung Yeshe Publications, ISBN 962-7341-33-9, pp.134 & 205.