Burckhardt, Jacob, 1818-1897
Harper Torchbooks, 1968
Buku Teks SO
Durant, Will
Simon and Schuster, 1953
Buku Teks SO
edited with introductions by Joan Mickelson-Gaughan
Scarecrow Press, 1991
Buku Referensi
Webster, Hutton
D.C. Heath, 1947
Buku Teks SO
Wallbank, T. Walter
Scott, Foreman, 1965
Buku Teks