- Author: Douglas Walton
- Language: English
- Year: 1996
- Author: Douglas Walton
- Language: English
- Year: 1998
- Author: John Woods, Douglas Walton
- Language: English
- Year: 1989
- Author: Douglas Walton
- Language: English
- Year: 1999
- Author: Douglas Walton Fabrizio Macagno Giovanni Sartor
- Language: English
- Year: 2021
- Author: Douglas Walton Alan Brinton
- Language: English
- Year: 1997
- Author: Douglas Walton
- Language: English
- Year: 2005
- Author: Fabrizio Macagno Douglas Walton
- Language: English
- Year: 2017
- Author: Douglas Walton
- Language: English
- Year: 2013