Cita APA (7th ed.)
Hill, N. (1977). Success through a positive mental attitude. A Kangaroo book.
Cita Chicago (17th ed.)
Hill, Napoleon. Success Through a Positive Mental Attitude. New York: A Kangaroo book, 1977.
Cita MLA (9th ed.)
Hill, Napoleon. Success Through a Positive Mental Attitude. A Kangaroo book, 1977.
Atenció: Aquestes cites poden no estar 100% correctes.