Myers, Gustavus, author
Random House, 1943
Buku Teks
Rand McNally and Company.
Rand Mcnally & Company, 2006
Buku Teks
Departement of Stetes Based, 1949
Buku Teks
Kemmerer, Donald L., author
Littlefield, Adams, 1956
Buku Teks
Fairbank, John K. (John King), author
Harvard University Press, 1948.
Buku Teks