- Author: Wolff Robert Paul
- Language: English
- Year: 2013
- Author: Wolff Robert Paul
- Language: English
- Author: J.L. Shaw Michael Hemmingsen (eds.)
- Language: English
- Year: 2011
- Author: Robert Paul Wolff
- Language: English
- Year: 2013
- Author: Robert Paul Wolff, John Roemer David Schweickart
- Language: English
- Year: 2013