Waldo, Dwright, author
Random House, 1965
Buku Teks
White, Leonard D., author
Macmillan, 1955
Buku Teks
Pritchett, C. Herman, author
University of North California Press, 1943
Buku Teks
Simon, Herbert A., author
Alfred A. Knopf, 1973
Buku Teks
Buku Teks