- Author: Charles W. L. Hill
- Language: English
- Year: 2021
- Author: Charles W. L. Hill
- Language: English
- Year: 2021
- Author: Charles W.L. Hill, G. Tomas M. Hulthill hult
- Language: English
- Year: 2018
- Author: Charles W.L. Hill, G. Tomas M. Hult
- Language: English
- Year: 2022
- Author: Charles W. L. Hill PhD
- Language: English
- Year: 2022
- Author: Charles W. L. Hill
- Language: English
- Year: 2021
- Author: Charles W. L. Hill PhD
- Language: English
- Year: 2020
- Author: Charles W. L. Hill
- Language: Spanish
- Year: 2010
- Author: Charles W. L. Hill, Thomas McKaig, G. Tomas M. Hult, Tim Richardson
- Language: English
- Year: 2018