Potter, Jack M.
The University of Chicago Press, 1976
Buku Teks
Gavin, James M.
Random Hause, 1968
Buku Teks
Kluwer Academic Publishers, 1998
Buku Teks
editor, Wolfgang Kruse
Press and Information Office of Land Berlin, 1979
Buku Teks
MacAvoy, Paul W.
Palgrave Macmillan, 2003
Buku Teks