Gaya APA
Gartside, L. (1981).
Model business letters (3).
Jakarta:
a longman group company.
Gaya Chicago
Gartside, L.
Model business letters.
3
Jakarta:
a longman group company,
1981.
Buku.
Gaya MLA
Gartside, L.
Model business letters.
3
Jakarta:
a longman group company,
1981.
Buku.
Gaya Turabian
Gartside, L.
Model business letters.
3
Jakarta:
a longman group company,
1981.
Buku.