Gaya APA
Covey, S, R. (2004).
The 7 Habits Of Highly Effective People: Powerful Lessons In Personal Change .
London, New York:
Simon & Schuster UK Ld.
Gaya MLA
Covey, Stephen, R..
"The 7 Habits Of Highly Effective People: Powerful Lessons In Personal Change".
London, New York:
Simon & Schuster UK Ld,
2004.
Text.