Carnegie, D. (1940). How to win friend and influences people (6ª ed.). Pocket Books.
Cita Chicago (17th ed.)Carnegie, Dale. How to Win Friend and Influences People. 6ª ed. Pocket Books, 1940.
Cita MLA (9th ed.)Carnegie, Dale. How to Win Friend and Influences People. 6ª ed. Pocket Books, 1940.
Atenció: Aquestes cites poden no estar 100% correctes.