Gaya APA
rein, D, P. (1985).
Grolier Advanced English Course 4 .
the United States of America:
[s.l].Grolier International. Inc.
Gaya MLA
rein, David, P..
"Grolier Advanced English Course 4".
the United States of America:
[s.l].Grolier International. Inc,
1985.
Koleksi Elektronik.