Myers, Margaret G.
Columbia University Press , 1970
Buku Teks
Rae, John B.
Mc Graw-Hill Book Company, 1949
Buku Teks
Beard, Charles A.
New Home Library, 1944
Buku Teks
Wright, Chester Whitney
McGraw-Hill, 1949
Buku Teks
Bemis, Samuel Flagg, 1891-1973
Holt, Rinehart and Winston, 1965
Buku Teks