Von Hesse, E. F. (1959). So to speak: A practical training course for developing a beautiful speaking voice (Rev. ed.). Lippincott.
Chicago-referens (17:e uppl.)Von Hesse, Elizabeth Ferguson. So to Speak: A Practical Training Course for Developing a Beautiful Speaking Voice. Rev. ed. Philadelphia: Lippincott, 1959.
MLA-referens (9:e uppl.)Von Hesse, Elizabeth Ferguson. So to Speak: A Practical Training Course for Developing a Beautiful Speaking Voice. Rev. ed. Lippincott, 1959.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.