APA Style
Azar, B, S. (1989).
Understanding and using English grammar 2 ed. (2).
United States of America:
Prentice Hall.
MLA Style
Azar, Betty, Schrampfer.
"Understanding and using English grammar 2 ed.".
2
United States of America:
Prentice Hall,
1989.
Bahasa Inggris.