Gaya APA
Napa, P, A. (1991).
Basic English Grammar: With Clear Explanation, Examples and Exercises .
Yogyakarta:
PT Kanisius.
Gaya MLA
Napa, Pieter, A..
"Basic English Grammar: With Clear Explanation, Examples and Exercises".
Yogyakarta:
PT Kanisius,
1991.
Texts.