APA
LEUNG K., E.C Tan, W.K To & Y.H. Pang. (2004). Challenging Problems In Mathematics. Singapore: Singapore Mathematical Society.
Chicago
LEUNG K.H, E.C Tan, W.K To and Y.H. Pang. 2004. Challenging Problems In Mathematics. Singapore: Singapore Mathematical Society.
Harvard
LEUNG K., E.C Tan, W.K To and Y.H. Pang. (2004). Challenging Problems In Mathematics. Singapore: Singapore Mathematical Society.
MLA
LEUNG K.H, E.C Tan, W.K To and Y.H. Pang. Challenging Problems In Mathematics. Singapore: Singapore Mathematical Society. 2004.