Gaya APA

PurwOkartun, N., Pieter, A, N. (1991). Basic English Grammar: With Clear Explanation, Examples And Exercises (-). Yogyakarta: Kanisius.

Gaya MLA

PurwOkartun, NasSirun., Pieter, A., Napa. "Basic English Grammar: With Clear Explanation, Examples And Exercises". - Yogyakarta: Kanisius, 1991. Text.