Gaya APA

Covey, S, R. (1989). The 7 Habits Effecive People The 7 Habits of Highly Effective People . New York: New York.Simon and Schuster.

Gaya MLA

Covey, Stephen, R.. "The 7 Habits Effecive People The 7 Habits of Highly Effective People". New York: New York.Simon and Schuster, 1989. Text.