- Author: Harold Ivan Smith
- Language: English
- Year: 2001
- Author: Harold Ivan Smith, Dr Alan D Wolfelt
- Language: English
- Year: 2011
- Author: Harold Ivan Smith
- Language: English
- Year: 2012
- Author: Harold Ivan Smith
- Language: English
- Year: 2017
- Author: Harold Ivan Smith
- Language: English
- Year: 2013