- Author: K. Raj Singh, Raymond Aaron, Dr. John Gray, Marci Shimoff
- Language: English
- Year: 2016
- Author: Durgesh Nandini Chauhan, Prabhu Raj Singh, Kamal Shah, Nagendra Singh Chauhan, Prabhu Raj Singh, Kamal Shah, Nagendra Singh Chauhan
- Language: English
- Year: 2020
- Author: Goyal Megh Raj, Singh Ajai
- Language: English
- Year: 2017
- Author: Bharat Raj Singh
- Language: English
- Year: 2013
- Author: R. Raj Singh
- Language: English
- Year: 2010
- Author: R. Raj Singh
- Language: English
- Year: 2010