Gaya APA

Sudarwati, T, M., Valentina, A. (2007). look ahead an english course : for senior high school students year XII (Cet . 9). Jakarta: Erlangga.

Gaya MLA

Sudarwati, Th., M., Valentina, Anna. "look ahead an english course : for senior high school students year XII". Cet . 9 Jakarta: Erlangga, 2007. Text.