Gaya APA

Sudarwati, T, M., Grace, E. (2007). Look Ahead Book 2 an English Course for SHS Students Year XI Science and Social Study Program . Yogyakarta: Erlangga.

Gaya MLA

Sudarwati, Th., M.., Grace, Eudia. "Look Ahead Book 2 an English Course for SHS Students Year XI Science and Social Study Program". Yogyakarta: Erlangga, 2007. Text.