- Author: Charles Hill
- Language: Spanish
- Year: 2021
- Author: Charles Hill
- Language: English
- Year: 2010
- Author: Samuel Charles Hill
- Language: English
- Year: 2015
- Author: Charles Hill
- Language: English
- Year: 2014
- Author: Charles Hill
- Language: English
- Year: 2021
- Author: Gareth Jones Melissa Schilling Charles Hill
- Language: English
- Year: 2019
- Author: Charles Hill, Gareth Jones, Gareth R. Jones
- Language: Spanish
- Year: 2010
- Author: Charles Hill G. Tomas M. Hult
- Language: English
- Year: 2019
- Author: Charles Hill
- Language: English
- Year: 2011
- Author: Charles Hill
- Language: English
- Year: 2011