Swami Muktananda - although teaching the traditional So on inhalation and ham on exhalation as a letter from 1968 to Franklin Jones reveals[REF] - later published a book[REF] teaching Ham on inhalation and sa on exhalation.
The teaching of Ham on inhalation and sa on exhalation is allegedly alluded to in a text of Kaśmir Śaivism, the Vijnana Bhairava: .