Graham, Malbone W.
Johns Hopkins Press, 1948
Buku Teks
Ferrell, Robert H., author
W.W. Norton, 1959
Buku Teks
Fisher, Roger, author
Harper Torchbooks, 1969
Buku Teks
Jones, Howard, author
Franklin Watt , 1985
Buku Teks
Alstyne, Richard W. van
Stanford University Press, 1947
Buku Teks