COVEY STEPHEN R. (1990). 7 HABITS OF HIGHLY EFFECTIVE PEOPLE: POWERFUL LESSONS IN PERSONAL CHANGE. FIRESIDE BOOK.
Dyfyniad Arddull ChicagoCOVEY STEPHEN R. 7 HABITS OF HIGHLY EFFECTIVE PEOPLE: POWERFUL LESSONS IN PERSONAL CHANGE. LONDON: FIRESIDE BOOK, 1990.
Dyfyniad MLACOVEY STEPHEN R. 7 HABITS OF HIGHLY EFFECTIVE PEOPLE: POWERFUL LESSONS IN PERSONAL CHANGE. FIRESIDE BOOK, 1990.
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