Rader, Melvin
Holt, Rinehart and Winston, 1966
Buku Teks
Ayer, A. J. (Alfred Jules), 1910-1989, author
Penguin Books, 1982
Buku Teks
Russell, Bertrand, 1872-1970, author
Oxford University Press, 1912
Buku Teks
Bentley, John Edward, author
Littlefield, Adams, 1958
Buku Teks
editor, Walter Leifer
Max Hueber verlag, Muchen, 1964
Buku Teks