Grew, Joseph Clark
Houghton Miffiln, 1952
Buku Teks
Berding, Andrew, author
Double Day, 1962
Buku Teks
Perkins,Dexter
Little, Brown and Company, 1944
Buku Teks
Lippmann, Walter, author
Little, Brown, 1943.
Buku Teks
Jones, Joseph Marion
Macmillan, 1944
Buku Teks