Gaya APA
Sandford, W, P. ().
Effective business speech / William Philips Sandford, Willard Hayes Yeager (4th ed.).
:
McGraw-Hill.
Gaya MLA
Sandford, William, Philips.
"Effective business speech / William Philips Sandford, Willard Hayes Yeager".
4th ed.
:
McGraw-Hill,
.
Referensi.