Covey, S. R. (2004). The 7 habits of highly effective people. Pocket books.
Chicago-стиль цитированияCovey, Stephan R. The 7 Habits of Highly Effective People. London: Pocket books, 2004.
MLA-цитированиеCovey, Stephan R. The 7 Habits of Highly Effective People. Pocket books, 2004.
Предупреждение: эти цитированмия не могут быть всегда правильны на 100%.