Departement of Stetes Based, 1949
Buku Teks
Reischauer, Edwin O., author
Harvard University Press, 1950
Buku Teks
Myers, Margaret G., author
Columbia University Press , 1970
Buku Teks
Mussatti, James
D. Van Nostrand Company, Inc., 1960
Buku Teks
Kemmerer, Donald L., author
Littlefield, Adams, 1956
Buku Teks