edited by William Line and Margery R. King
University of Toronto Press, 1956
Buku Teks
Goodman, Benny, author
Learning matters Ltd., 2008
Buku Teks
Levine, Joanne, author
Pearson, 2013
Buku Teks
Lundin, William, 1923- , author
American Management Association, 2009
eBooks
Edited by Ben G. Goedegebuure; Humberto R. Arango Sales; Gilberto Sotolongo Aguilar
Elsevier, 1991
Buku Teks