- Author: Wills John Elliot
- Language: English
- Year: 2001
- Author: Krasner Stephen D.
- Language: English
- Year: 2001
- Author: Gerstenfeld Manfred
- Language: English
- Year: 2005
- Author: Robert J. McMahon
- Language: English
- Year: 2003
- Author: Dougherty James E., Pfaltzgraff Robert L.
- Language: English
- Year: 1971