APA Style

Covey, S, R. (1989). The 7 Habits of Highly Effective People : Powerful Lessons in Personal Change / Stephen R. Covey . New York: Free Press.

MLA Style

Covey, Stephen, R.. "The 7 Habits of Highly Effective People : Powerful Lessons in Personal Change / Stephen R. Covey". New York: Free Press, 1989. หนังสือ (Book).