Joko, P.(2008).Interlanguage: English for senior high school studen XI Language study programme .Jakarta:Pusat Pembukuan Departemen Pedidikan Nasional.
Gaya MLA
Joko, P..Interlanguage: English for senior high school studen XI Language study programme.Jakarta:Pusat Pembukuan Departemen Pedidikan Nasional,2008.Text.