Girard, Joe y Casemore, Robert. How to sell yourself (Cómo venderse a sí mismo). New York: Simon and Shuster, 1979.
4 Girard, Joe, How to sell anything to anybody, Fireside.
5 Girard, Joe y Casemore, Robert. Cómo venderse a sí mismo, p. 74.
6 Girard, Joe y Casemore, Robert. How to sell anything to anybody (Cómo vender cualquier cosa a cualquier persona). New York, EE.UU.: Simon and Shuster, 1977.
7 Ibid.
Girard, Joe y Casemore Robert. How to sell yourself. New York: Simon and Shuster, 1979.