Gaya APA

Koh, D, C. (2007). Science In Focus Biology 'O' Level. Pratikal Workbook . Singapore: Pearson Education South Asia Pte Ltd.

Gaya MLA

Koh, Dr., Caroline. "Science In Focus Biology 'O' Level. Pratikal Workbook". Singapore: Pearson Education South Asia Pte Ltd, 2007. Text.