Covey, S. R. The 7 habits of highly effective people: Restoring the character ethic (Revised edition.).
Цитирование в стиле Чикаго (17-е изд.)Covey, Stephen R. The 7 Habits of Highly Effective People: Restoring the Character Ethic. Revised edition.
Цитирование MLA (8-е изд.)Covey, Stephen R. The 7 Habits of Highly Effective People: Restoring the Character Ethic. Revised edition.
Предупреждение: эти цитированмия не могут быть всегда правильны на 100%.