Butterfield, J. (2010). Verbal communication: Illustrated course guides (Second edition.). Course Technology, Cengage Learning.
Цитирование в стиле Чикаго (17-е изд.)Butterfield, Jeff. Verbal Communication: Illustrated Course Guides. Second edition. Australia: Course Technology, Cengage Learning, 2010.
Цитирование MLA (9-е изд.)Butterfield, Jeff. Verbal Communication: Illustrated Course Guides. Second edition. Course Technology, Cengage Learning, 2010.
Предупреждение: эти цитированмия не могут быть всегда правильны на 100%.