APA (7e ed.) Bronvermelding

COVEY, S. R. (1990). The 7 habits of higly effective people: Powerful lessonin personal change. A Fireside Book.

Chicago (17e ed.) Bronvermelding

COVEY, Stephen R. The 7 Habits of Higly Effective People: Powerful Lessonin Personal Change. New York: A Fireside Book, 1990.

MLA (9e ed.) Bronvermelding

COVEY, Stephen R. The 7 Habits of Higly Effective People: Powerful Lessonin Personal Change. A Fireside Book, 1990.