McMurry, John, author
Prentice-Hall, 1994
Buku Teks
Bruns, Ramon O., author
Burgess Publishing Company, 1974
Buku Teks
Gerking, Shelby D., author
Burgess, 1970
Buku Teks
Patterson, C.O. Pat, author
Burgess Publishing , 1973
Buku Teks
Fairley, James L., author
Van Nostrand , 1966
Buku Teks