White, David Manning
Macmillan, 1983
Buku Teks
Shaw, Bernard, 1856-1950, author
Penguin Books, 1934
Buku Teks
Siegel, James T., 1937-, author
University of California Press, 1969
Buku Teks
Daman, Jan
Contact, 1968
Buku Teks
Huber, Carlo, author
The Council for Research Values and Philosophy , 2001
Buku Teks