Montgomery, B.
The Word Publishing Comp, [date of publication not identified]
Buku Teks
Gildersleeve, B.L.
Macmillan, 1948
Buku Teks SO
edited by Jerry D. Lewis
Bernard Geis Associates, 1962
Buku Teks
Wint, Guy
Frederick A. Praeger, 1958
Buku Teks SO
Kennan, George F., 1904-
Little, Brown, 1967
Buku Teks SO