Gaya APA
O'Gorman, F, K, D, A, C, D.
(1962).
English Business Letters
.
Essex:
Longman Group Limited.
Gaya MLA
O'Gorman, F.W., King,, D., Ann, Cree,, David.
"English Business Letters".
Essex:
Longman Group Limited,
1962.
BK.