APA (7th ed.) Citation

Tay, B. (2007). Science in focus Biology `O` Level. Longman.

Chicago Style (17th ed.) Citation

Tay, Beverly. Science in Focus Biology `O` Level. Longman, 2007.

MLA (8th ed.) Citation

Tay, Beverly. Science in Focus Biology `O` Level. Longman, 2007.

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