- Author: Ken Wilber
- Language: English
- Year: 1998
- Author: Ken Wilber
- Language: German
- Author: Ken Wilber
- Language: German
- Year: 2001
- Author: Wilber (Pete) W. Caldwell
- Language: English
- Year: 2008
- Author: Reid Legh Wilber
- Language: English
- Year: 2009
- Author: Ken Wilber
- Language: French
- Year: 1987
- Author: Ken Wilber
- Language: English
- Year: 2000
- Author: Ken Wilber
- Language: English
- Year: 2001
- Author: Ken Wilber
- Language: English
- Year: 2001