APA (7th ed.) Citation

Muhammad Umar. (2008). Kekalkan kebersihan udara. Jurus Prinsip.

Chicago Style (17th ed.) Citation

Muhammad Umar. Kekalkan Kebersihan Udara. Kuala Lumpur: Jurus Prinsip, 2008.

MLA (9th ed.) Citation

Muhammad Umar. Kekalkan Kebersihan Udara. Jurus Prinsip, 2008.

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