Singing and Communicating in English by
"Offers clear, concise explanations with pertinent examples. The author's vast experience as a diction coach is evident on every page. The linked website augments the text's usefulness. Singers, voice teachers, and coaches will find Singing and Communicating in English an excellent resource." --Journal of Singing
Voice and the Actor by 
International Phonetic Alphabet for Singers by 
Alfred's IPA Made Easy by
This handy guidebook is an easy reference for the symbols used in IPA: what they look like and how they are pronounced. Example words for every symbol are included in English, Latin, Italian, German, French, and Spanish. And an online resource includes recorded demonstrations of every sound
