- Author: Alan D Wolfelt, Alan D Wolfelt, Kirby J. Duvall
- Language: English
- Year: 2012
- Author: Alan D Wolfelt, Alan D Wolfelt, Kirby J. Duvall
- Language: English
- Year: 2012
- Author: Alan D Wolfelt, Alan D Wolfelt, Raelynn Maloney
- Language: English
- Year: 2011
- Author: Alan D Wolfelt, Alan D Wolfelt
- Language: English
- Year: 2002
- Author: Alan D Wolfelt, Alan D Wolfelt
- Language: English
- Year: 2013
- Author: Alan D. Wolfelt Alan D Wolfelt Kirby J. Duvall
- Language: English
- Year: 2010
- Author: Alan D. Wolfelt PhD
- Language: English
- Year: 2005
- Author: Alan D. Wolfelt PhD
- Language: English
- Year: 2001