APA Style

Leong, O, H., Aik, E, A, J. (2006). Chemistry Expression: Theory Workbook 'O' Level Science . Singapore: EPB Pan Pacific.

MLA Style

Leong, Oon, Hock., Aik, Edmund, Ang, Joon. "Chemistry Expression: Theory Workbook 'O' Level Science". Singapore: EPB Pan Pacific, 2006. Text.