Bemis, Samuel Flagg, 1891-1973, author
Holt, Rinehart and Winston, 1965
Buku Teks
Treat, Payson J., author
Peter Smith, 1963
Buku Teks
Myers, Gustavus, author
Random House, 1943
Buku Teks
Myers, Margaret G., author
Columbia University Press , 1970
Buku Teks
Kemmerer, Donald L., author
Littlefield, Adams, 1956
Buku Teks