APA (7th ed.) Citation

Oon, H., & Oon, H. (2013). Singapore (Seventh edition.). New Holland.

Chicago Style (17th ed.) Citation

Oon, Helen, and Helen Oon. Singapore. Seventh edition. London: New Holland, 2013.

MLA (9th ed.) Citation

Oon, Helen, and Helen Oon. Singapore. Seventh edition. New Holland, 2013.

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