APA (7th ed.) Citation

Bong, H. S. (2009). Why? Ilmu Pengetahuan Alam. Elex Media Komputindo.

Chicago Style (17th ed.) Citation

Bong, Heo Soon. Why? Ilmu Pengetahuan Alam. Elex Media Komputindo, 2009.

MLA (8th ed.) Citation

Bong, Heo Soon. Why? Ilmu Pengetahuan Alam. Elex Media Komputindo, 2009.

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