- Author: Eldon S. Hendriksen
- Language: English
- Year: 1991
- Author: Options Institute
- Language: English
- Year: 1990
- Author: Charles J. Woelfel
- Language: English
- Year: 1994
- Author: Benton E. Gup
- Language: English
- Year: 1995
- Author: Michael A. Belch George E. Belch
- Language: English
- Year: 2003
- Author: Allen Webster
- Language: Spanish
- Year: 2001
- Author: Options Institute
- Language: English
- Year: 1994
- Author: Stephen A. Ross
- Language: English
- Year: 2000
- Author: Слейтер Р.
- Language: Русский
- Year: 1996
- Author: Options Institute
- Language: English
- Year: 1990