APA (7th ed.) Citation

Tan, K. L. (2002). Online Psychological Testing System (OPTS) / Tan Kien Leong.

Chicago Style (17th ed.) Citation

Tan, Kien Leong. Online Psychological Testing System (OPTS) / Tan Kien Leong. 2002.

MLA (9th ed.) Citation

Tan, Kien Leong. Online Psychological Testing System (OPTS) / Tan Kien Leong. 2002.

Warning: These citations may not always be 100% accurate.