Hall, Walter Phelps, author
Ginn and Company, 1953
Buku Teks
Larson, Laurence M., author
Holt , 1926
Buku Teks
Morton, A.L., author
Victor Gollancz, 1938
Buku Teks
editor-in-Chief L. Crispin Warmington
Butterworth, 1950
Buku Teks
Trevelyan, George Macaulay, 1876-1962, author
Longmans , Green, 1948
Buku Teks