Gaya APA
New Concept English Practice and Progress. (1991).
Yogyakarta:
Kanisius.
Gaya Chicago
New Concept English Practice and Progress.
ed.7.
Yogyakarta:
Kanisius,
1991.
.
Gaya MLA
New Concept English Practice and Progress.
ed.7.
Yogyakarta:
Kanisius,
1991.
.
Gaya Turabian
New Concept English Practice and Progress.
Yogyakarta:
Kanisius,
1991.
.