Carmichael, Leonard, author
Random House, 1957
Buku Teks
Ratcliffe, Matthew, author
Palgrave Macmillan, 2007
Buku Teks
Carlson, Neil R., author
Allyn and Bacon, [date of publication not identified]
Buku Teks
Carlson, Neil R., author
[publisher not identified], 1997
Buku Teks
Isaacson, Robert L., author
Harper & Row, 1965
Buku Teks