Jansen, Ernst P.
Kluwer, 1994
Buku Teks
Kortmann, C.A.J.M.
Kluwer Law International, 2007
Buku Teks
Rodgers, William H.
West Publishing, 1994
Buku Teks
Kubasek, Nancy K.
Pearson - Prentice Hall, 2005
Buku Teks
Gaba, Jeffrey M.
United States of America, 1994
Buku Teks