Feiling, Keith
Macmillan, 1951
Buku Teks
Gilbert, Bentley B.
B.T. Bastford, Ltd., 1970
Buku Teks
Brittain, Herbert, Sir
George Allen and Unwin, 1959
Buku Teks
Child, John, author
George Allen and Unwin, 1969
Buku Teks
Williamson, James A., author
Macmillan, 1962
Buku Teks