The Upanishads : Katha, Iśa, kena, and Mundaka : translated from the Sanskrit with introductions embodying a general survey and the metaphysics and psychology of the Upanishads, and with notes and explanations based on the commentary of Śrī Śaṅkarācharya, the great ninth-century philosopher and saint of India - Nikhilananda (SAMP early 20th-century Indian books project, 1964)