Sayles, Leonard R.
McGraw-Hill , 1964
Buku Teks
Porter, Donald E.
International , 1964
Buku Teks
Lundgren, Earl F.
Confield, 1974
Buku Teks
Moorhead, Gregory
South-Western Cengage Learning, 2012
Buku Teks
Williamson, Oliver E.
Markham, 1967
Buku Teks