Gaya APA
Cooper, D, R, C, D, R.
(2006).
Business research methods.--
(
Ed. 9.--)
.
America:
McGraw-Hill.
Gaya MLA
Cooper, Donald, R., Cooper,, Donald, R..
"Business research methods.--".
Ed. 9.--
America:
McGraw-Hill,
2006.
Buku.