Welsch, Glenn A.
Irwin, 1997
Buku Teks
Rachlin, Robert
American Management Association, 1996
eBooks
Meigs, Walter B.
McGraw-Hill, 1979
Buku Teks
Harrison, Walter T.
Pearson education, 2015
Buku Teks
Eskew, Robert K.
Random House Business Division, 1989
Buku Teks