Gaya APA
Covey, S, R.
(1994).
The 7 Habits of Highly Effective People
.
Amerika Serikat:
PT Gramedia Pustaka Utama.
Gaya MLA
Covey, Stephen, R..
"The 7 Habits of Highly Effective People".
Amerika Serikat:
PT Gramedia Pustaka Utama,
1994.
Text.