Enger, Eldon D., author
McGraw-HIll, 2003
Buku Teks
Duff, Michael F., author
Burgess, 1973
Buku Teks
Mertens, Thomas R., author
Burgess, 1968
Buku Teks
Hehman, Robert F., author
Costomized Publishing Division, 1976
Buku Teks
Yarbrough, James D., author
Burgess Publishing, 1970
Buku Teks