- Author: Robert Kaplan
- Language: Italian
- Year: 2001
- Author: Robert Kaplan
- Language: Italian
- Year: 2001
- Author: Kaplan Robert, Kaplan Ellen
- Language: English
- Year: 2011
- Author: Kaplan Robert, Kaplan Ellen
- Language: English
- Year: 2012
- Author: Robert Kaplan Ellen Kaplan
- Language: English
- Year: 2014
- Author: Robert Kaplan
- Language: English
- Year: 2001
- Author: Robert Kaplan Ellen Kaplan
- Language: English
- Year: 2014
- Author: Robert Kaplan
- Language: English
- Year: 2005
- Author: Robert Kaplan Ellen Kaplan
- Language: English
- Year: 2008