Schrampfer, A., B.(1989).Understanding and using English grammar. Second Edition / Betty Schrampfer Azar (Ed.ke-2, Cet.4).New Jersey:Prentice Hall Regents.
Gaya MLA
Azar, Betty, Schrampfer."Understanding and using English grammar. Second Edition / Betty Schrampfer Azar".Ed.ke-2, Cet.4New Jersey:Prentice Hall Regents,1989.Textbook.