Gaya APA
Peterson, P, W. (1980).
Changing times, changing tenses: a review of the English tense system .
Washington:
English teacing Divsion Educatioal and Cultura Affairs.
Gaya MLA
Peterson, Patricia, Wilcox.
"Changing times, changing tenses: a review of the English tense system".
Washington:
English teacing Divsion Educatioal and Cultura Affairs,
1980.
Text.