APA (7th ed.) Citation

Obert, K. B., & Chicurel, S. R. (2005). Geography of the voice.

Chicago Style (17th ed.) Citation

Obert, Kerrie B., and Steven R. Chicurel. Geography of the Voice. Think Voice International, 2005.

MLA (9th ed.) Citation

Obert, Kerrie B., and Steven R. Chicurel. Geography of the Voice. 2005.