Gaya APA
Azar, B, S. (1989).
Understanding And Using English Grammar: Second Edition (Ed. 2, Cet. 1).
usa:
Prentice Hall.
Gaya MLA
Azar, Betty, Schrampfer.
"Understanding And Using English Grammar: Second Edition".
Ed. 2, Cet. 1
usa:
Prentice Hall,
1989.
Book.