Norton, Thomas James, author
America`s Future, 1946
Buku Teks
Norton, Thomas James
America`s Future, Inc., 1946
Buku Teks
Mitchell, Broadus, author
Oxford University Press, 1964
Buku Teks
introduction by Edward G. Smith
Barnes & Noble, 1966
Buku Teks
Farrand, Max, author
Yale University Press, 1962
Buku Teks