Dyfyniad APA

Covey Stephen R. (2004). Seven habits Of Highly Effective People. Simon Schuster.

Dyfyniad Arddull Chicago

Covey Stephen R. Seven Habits Of Highly Effective People. London: Simon Schuster, 2004.

Dyfyniad MLA

Covey Stephen R. Seven Habits Of Highly Effective People. Simon Schuster, 2004.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.