Gaya APA
Sudarwati, T, M., Grace, E. (2007).
Look Ahead Book 1, An English Course for Senior High School Students Year X .
Yogyakarta:
Erlangga.
Gaya MLA
Sudarwati, Th., M.., Grace, Eudia.
"Look Ahead Book 1, An English Course for Senior High School Students Year X".
Yogyakarta:
Erlangga,
2007.
Text.