
- Author: Richard D. Williamson
- Language: English
- Year: 2012

- Author: Richard E. Williamson Hale F. Trotter
- Language: English
- Year: 2003

- Author: Richard E. Williamson Hale F. Trotter
- Language: English
- Year: 1995

- Author: Richard T. Williamson
- Language: English
- Year: 2003

- Author: Richard E. Williamson Richard H. Crowell Hale F. Trotter
- Language: English
- Year: 1968