Gaya APA

Widyastuti, A., Sukur, S, G. (2005). Contextual Tenses For Effective English Communication (-). Jakarta: Bhuana Ilmu Populer.

Gaya MLA

Widyastuti, Ana., Sukur, Silvester, Goridus. "Contextual Tenses For Effective English Communication". - Jakarta: Bhuana Ilmu Populer, 2005. Text.