Gaya APA
Wardhaugh, R, W, R. (1972).
Woorbook to accompany introduction to linguistics.-- .
America:
McGraw-Hill.
Gaya MLA
Wardhaugh, Ronald., Wardhaugh,, Ronald..
"Woorbook to accompany introduction to linguistics.--".
America:
McGraw-Hill,
1972.
Buku.