Gaya APA
Sarah, S, M, A.
(1993).
How to Inprove Your CUSTOMER SERVICE
.
Jakarta:
PT Gramedia Pustaka Utama.
Gaya MLA
Sarah, Stephen, Macaulay, And.
"How to Inprove Your CUSTOMER SERVICE".
Jakarta:
PT Gramedia Pustaka Utama,
1993.
Text.