APA (7th ed.) Citation

N, E. N., & Youngsun, C. (2019). Why?: Theory of Relativity (Teori Relativitas). PT Elex Media Komputindo.

Chicago Style (17th ed.) Citation

N, Endah Nawang, and Cho Youngsun. Why?: Theory of Relativity (Teori Relativitas). PT Elex Media Komputindo, 2019.

MLA (8th ed.) Citation

N, Endah Nawang, and Cho Youngsun. Why?: Theory of Relativity (Teori Relativitas). PT Elex Media Komputindo, 2019.

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