McDonald Klimek, M., Obert, K. B., & Steinhauer, K. (2005). Estill voice training system. Estill Voice Training Systems International.
芝加哥风格引文McDonald Klimek, Mary, Kerrie B. Obert, 与 Kimberly Steinhauer. Estill Voice Training System. [Pittsburgh, Pa.]: Estill Voice Training Systems International, 2005.
MLA引文McDonald Klimek, Mary, et al. Estill Voice Training System. Estill Voice Training Systems International, 2005.
警告：这些引文格式不一定是100％准确.