- Author: E. David Gregory
- Language: English
- Year: 2010
- Author: David Gregory Monaco
- Language: English
- Year: 2013
- Author: David Gregory
- Language: English
- Year: 2016
- Author: David Gregory
- Language: English
- Year: 2012
- Author: Baldwin David, Gregory Philippa, Jones Michael
- Language: English
- Year: 2014
- Author: Dan Stone David Gregory
- Language: English
- Year: 2014
- Author: Charles David Gregory
- Language: English
- Year: 1992