Ludwig Pesch, The Illustrated Companion to South Indian Classical Music (New Delhi: Oxford University Press, 1999) is a lengthy introduction to Carnatic music, with a useful chapter on voice training.
John Potter and Neil Sorrell, A History of Singing. New York: Cambridge University Press, 2012. (Sources and references, p. 310)
Find a copy of the Oxford Illustrated Companion to South Indian Classical Music
- on the publisher’s website: Oxford University Press
- in a library near you via WorldCat.org
- from one of several Indian distributors and online bookstores