MacIver, Robert M., author
Oxford, 1926
Buku Teks
edited by Peter G. Bruce
Cambridge University Press, 1997
Buku Teks
edited Nancy L. Rosenblum and Robert C. Post
Princeton University Press , 2002
Buku Teks
Artikel Jurnal
Kittel, Charles, author
John Wiley & Sons, 1986
Buku Teks