Cita APA (7th ed.)

Von Hesse, E. F. (1959). So to speak: A practical training course for developing a beautiful speaking voice (Rev. ed.). Lippincott.

Cita Chicago (17th ed.)

Von Hesse, Elizabeth Ferguson. So to Speak: A Practical Training Course for Developing a Beautiful Speaking Voice. Rev. ed. Philadelphia: Lippincott, 1959.

Cita MLA (9th ed.)

Von Hesse, Elizabeth Ferguson. So to Speak: A Practical Training Course for Developing a Beautiful Speaking Voice. Rev. ed. Lippincott, 1959.