Original: He continued to study with many masters, of all schools of Tibetan Buddhism, especially Dudjom Rinpoche, Dilgo Khyentse Rinpoche, and Nyoshul Khenpo Rinpoche.
Simplified: He continued to study with many masters of all schools of Tibetan Buddhism, especially His Holiness Dudjom Rinpoche and His Holiness Dilgo Khyentse Rinpoche.