Henkin, Louis
Columbia University Press, 1958
Buku Teks
Bechhoefer, Bernhard G.
Brookings Institution, 1961
Buku Teks
Edward, David V.
Holt, Rinehart and Winston, 1969
Buku Teks
Millis, Walter
Atheneum, 1965
Buku Teks
Richard Dean Burns, editor in chief
Charles Scribner's Sons, 1993
Buku Referensi