Tagliaferri, Louis E.
Successful supervision : a self-teaching guide
John Wiley & Sons, 1979
 Buku Teks
Fernandez, Judi N., 1941-
Using CP/m: a self-teaching guide
John Wiley & Sons, 1980
 Buku Teks SO
Ivey, Paul W.
Successful salesmanship / by Paul W. Ivey, Walter Horvath
Prentice-Hall, 1961
 Buku Teks
Fernald, Charles H.
Salesmanship
Prentice-Hall, 1959
 Buku Teks
Jenks, Ernest E.
Salesmanship
Alexander hamilton Institute, 1962
 Buku Teks