Welch, Joseph N.
Houghton Miffiln, 1956
Buku Teks
Amery, L.S.
Oxford University Press, 1953
Buku Teks
Corwin, Edward S.
William Sloane, 1949
Buku Teks
Cox, Archibald, 1912-2004
Houghton Mifflin, 1987
Buku Teks
Jennings, Ivor, Sir, 1903-1965
Hodder and Stoughton, 1979
Buku Teks