<hi xmlns="http://www.tei-c.org/ns/1.0" rend="bold">Coward, Harold G. / Raja, K. Kunjunni</hi> (1990): <hi xmlns="http://www.tei-c.org/ns/1.0" rend="italic">The Encyclopedia of Indian Philosophies</hi>. 5: The Philosophy of the Grammarians. Princeton: Princeton University Press.