Gaya APA
Certificate of proficiency english practice. (1979).
tempaterbit:
penerbit.
Gaya Chicago
Certificate of proficiency english practice.
Edisi.
tempaterbit:
penerbit,
1979.
Text.
Gaya MLA
Certificate of proficiency english practice.
Edisi.
tempaterbit:
penerbit,
1979.
Text.
Gaya Turabian
Certificate of proficiency english practice.
tempaterbit:
penerbit,
1979.
Print.