Montgomery, B.
The Word Publishing Comp, [date of publication not identified]
Buku Teks
Gildersleeve, B.L.
Macmillan, 1948
Buku Teks
Kennan, George F., 1904-
Little, Brown, 1967
Buku Teks
Hawke, Bob
William Heinemann Australia, 1994
Buku Teks
Newton, Virgil Miller, 1904-1977
The Iowa State University Press, 1961
Buku Teks