Lakos, Amos, author
Westview Press, 1989
Buku Referensi
Reisman, William Michael, 1939-, author
Yale University Press, 1971
Buku Teks
Klotz. James M., author
Kluwer, 2008
Buku Teks
K.G. Saur, 1981
Buku Referensi
Sen, B., author
Martinus Nijhoff, 1965
Buku Teks