Quarles, Benjamin
Macmillan, 1969
Buku Teks
Drotning, Phillip T.
Doubleday, 1968
Buku Teks SO
Lomax, Louis E
Harper & Brothers Publishers, 1962
Buku Teks SO
edited by Michael Rines
Gower in Association with Marketing Magazine, 1981
Buku Teks
Skousen, Philip L.
McGraw-Hill, 2011
Buku Teks