Nimmer, Raymond T.
The Michie Company, 1992
Buku Teks
Volker, E.L.M., author
Kluwer, 1985
Buku Teks
Thorne, W.J., author
Oxford University Press , 1948
Buku Teks
Bradford, Frederick A., author
Longmans, Green, 1932
Buku Teks
Rodgers, Raymond, author
Alexander Hamiltion Institute, 1962
Buku Teks