Citazione APA

Covey, S. R. (1999). Seven habits of highly effective people (1st.). Pocket books.

Stile di citazione Chicago

Covey, Stephen R. Seven Habits of Highly Effective People. 1st. London: Pocket books, 1999.

Citazione MLA

Covey, Stephen R. Seven Habits of Highly Effective People. 1st. Pocket books, 1999.

Attenzione: Queste citazioni potrebbero non essere precise al 100%.