edited with introductions by Joan Mickelson-Gaughan
Scarecrow Press, 1991
Buku Referensi
Hughes, Paul L., author
Littlefield, Adams, 1956
Buku Teks
Weber, Eugen, author
Boston: D.C.Heath and Company, (1959).
Buku Teks
Burckhardt, Jacob, author
Harper Torchbooks, 1968
Buku Teks
Hale, John R., author
Time-Life International, 1969
Buku Teks