Davis, Mackenzie Leo, 1941-
McGraw-Hill, 2008
Buku Teks
Davis, Mackenzie Leo, 1941-
McGraw-Hill, 2013
Buku Teks
Centre for research of human resources and the nvironment University of Indonesia, 1991
Buku Referensi
Salvato, Joseph A.
John Wiley & Sons, 1982
Buku Teks
Sawyer, Clair N.
McGraw-Hill, 2003
Buku Teks