Coulson, Noel J., author
University Press, 1971
Buku Teks
Coertze, R.D., author
ABRA , 1987
Buku Teks
Carsrud, Alan L., author
Springer, 2011
eBooks
Hutley, F.C. (Francis Charles)
Law Book, Co., 1975
Buku Teks
Atwood, Christee Gabour, author
American Society for Training & Development, 2007
eBooks