Princenton University Press , 1965
Buku Teks
edited by Werner Sichel
Ann Arbor, 1970
Buku Teks
edited by Sylvester E. Berki
Health, 1966
Buku Teks
Hovenkamp, Herbert, author
West Publishing, 1993
Buku Teks
Calkins, Richard M., author
Dow Jones-Irwin, 1981
Buku Teks