Mathews, John Mabry
Appleton-Century Company, 1938
Buku Teks
George-Braziller , 1963
Buku Teks
Coates, Benjamin Allen, author
Oxford University Press, 2016
eBooks
Fugate, Wilbur L., author
Little, Brown, 1982
Buku Teks
edited by Richard P. Stebbins
Published for the Council on Foreign Relations by Simon and Schuster, [1939-1970], 1963
Buku Teks