COVEY STEPHEN R. (1990). 7 HABITS OF HIGHLY EFFECTIVE PEOPLE: POWERFUL LESSONS IN PERSONAL CHANGE. FIRESIDE BOOK.
Chicago (17e ed.) BronvermeldingCOVEY STEPHEN R. 7 HABITS OF HIGHLY EFFECTIVE PEOPLE: POWERFUL LESSONS IN PERSONAL CHANGE. LONDON: FIRESIDE BOOK, 1990.
MLA (9e ed.) BronvermeldingCOVEY STEPHEN R. 7 HABITS OF HIGHLY EFFECTIVE PEOPLE: POWERFUL LESSONS IN PERSONAL CHANGE. FIRESIDE BOOK, 1990.
Let op: Deze citaties zijn niet altijd 100% accuraat.