APA (7th ed.) Citation

Nikhilananda Swami & Sankaracarya. (1949). The Upanishads. Harper.

Chicago Style (17th ed.) Citation

Nikhilananda Swami and Sankaracarya. The Upanishads. New York: Harper, 1949.

MLA (9th ed.) Citation

Nikhilananda Swami and Sankaracarya. The Upanishads. Harper, 1949.