- Author: Dr. P. Purushothama Raj and Dr. V. Ramasamy
- Language: English
- Year: 2012
- Author: P Purushothama Raj
- Language: English
- Year: 2013
- Author: P Purushothama Raj
- Language: English
- Year: 2008
- Author: P. Purushothama Raj
- Language: English
- Year: 2017