- Author: Raymond M. Smullyan Melvin Fitting
- Language: English
- Year: 1996
- Author: Raymond M. Smullyan Melvin Fitting
- Language: English
- Year: 1996
- Author: Raymond M. Smullyan Melvin Fitting
- Language: English
- Year: 1996
- Author: Raymond M. Smullyan Melvin Fitting
- Language: English
- Year: 1996
- Author: Raymond M. Smullyan Melvin Fitting
- Language: English
- Year: 1996