Tay, B. (2007). Biology InsightsO Level Theory WorkbookBeverly Tay ;consultant: Caroline Koh. Pearson Longman.
Čikaški stil citiranja (17. izdanje)Tay, Beverly. Biology InsightsO Level Theory WorkbookBeverly Tay ;consultant: Caroline Koh. Pearson Longman, 2007.
MLA način citiranja (8. izdanje)Tay, Beverly. Biology InsightsO Level Theory WorkbookBeverly Tay ;consultant: Caroline Koh. Pearson Longman, 2007.
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