Christy, V. A. (1979). Foundations in singing; a basic textbook in the fundamentals of technic and song interpretation (Medium-Low voice edition.).
Chicago-referens (17:e uppl.)Christy, Van A. Foundations in Singing; a Basic Textbook in the Fundamentals of Technic and Song Interpretation. Medium-Low voice edition. Dubuque, Iowa : Wm. C Brown, 1979.
MLA-referens (9:e uppl.)Christy, Van A. Foundations in Singing; a Basic Textbook in the Fundamentals of Technic and Song Interpretation. Medium-Low voice edition. 1979.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.