APA Style
Grolier Business Library : Writing Business Letters. (2001).
Hongkong:
Grolier Internasional Inc..
Chicago Style
Grolier Business Library : Writing Business Letters.
.
Hongkong:
Grolier Internasional Inc.,
2001.
Buku.
MLA Style
Grolier Business Library : Writing Business Letters.
.
Hongkong:
Grolier Internasional Inc.,
2001.
Buku.
Turabian Style
Grolier Business Library : Writing Business Letters.
Hongkong:
Grolier Internasional Inc.,
2001.
Buku.