Michael Beloved is one of the world's foremost commentators on the Bhagavad Gita and its application to yoga from multiple perspectives, including application of yoga to cultural activities (karma yoga), application of yoga to intellectual activities (buddhi yoga/jnana yoga), application of yoga to love and affection (bhakti yoga), application of yoga to mental and emotional maneuvers (kriya yoga), and application of yoga to psychic and supernatural focus (brahma yoga). In addition, he's translated the Bhagavad Gita very accurately and written a couple books on meditation and spirituality. Deep information on psychology and eastern philosophy abounds in his books.