Ronner, Heinz, author
Birkauser , 1987
Buku Teks
Gilchrist, Ellen, author
Little, Brown, 1984
Buku Teks
Hoffman, Frederick J.
The Free Press, 1962
Buku Teks
Gilchrist, Ellen, author
Little, Brown & Co., 2000
Buku Teks
Canfield, Leon H., author
Houghton Mifflin, 1954
Buku Teks