Gaya APA
Gartside, L.
(1989).
Model business letters
(
3rd.ed.)
.
Jakarta:
Penerbit Binarupa Aksara.
Gaya MLA
Gartside, Leonard.
"Model business letters".
3rd.ed.
Jakarta:
Penerbit Binarupa Aksara,
1989.
Teks.