Abcarian, Gilbert, editor
Charles Seribner's, 1970
Buku Teks
Ebenstein, William
Holt, Rinehart and Winston, 1962
Buku Teks SO
Joad, C.E.M.
Clarendon Press, 1959
Buku Teks
edited David Marsh and Gerry Stoker
Macmillan, 1995
Buku Teks SO
Lipson, Leslie
Prentice-Hall, 1954
Buku Teks SO