Ward, Ian, author
Routledge. Cavendish. Taylor & Francis Group, 2004
Buku Teks
Puckett, Kent, author
Cambridge University Press, 2016
Buku Teks
Finch, John, author
Sweet & Maxwell, 1974
Buku Teks
Kelsen, Hans, author
Clarendon Press Oxford, 1992
Buku Teks
Finch, John, author
Sweet & Maxwell, 1970
Buku Teks