Cita APA

Covey, S. R. 1., & Covey, S. R. 1. (1990). The seven habits of highly effective people: Restoring the character ethic (1. edition.). New York, New York: Fireside.

Citación estilo Chicago

Covey, Stephen R. 1932-, y Stephen R. 1932- Covey. The Seven Habits of Highly Effective People: Restoring the Character Ethic. 1. edition. New York, New York: Fireside, 1990.

Cita MLA

Covey, Stephen R. 1932-, y Stephen R. 1932- Covey. The Seven Habits of Highly Effective People: Restoring the Character Ethic. 1. edition. New York, New York: Fireside, 1990.