Eyestone, Robert
John Wiley & Sons, 1978
Buku Teks
Luthans, Fred, author
Macmillan, 1976
Buku Teks
Quigley, Marian, author
IRM Press, 2005
Buku Teks
edited by Kurt Finsterbusch
McGraw-Hill, 2006
Buku Teks
Currie, Elliott, author
Little, Brown, 1984
Buku Teks