Hoffding, Harold, author
Macmillan, 1955
Buku Teks
Mayer, Frederick, author
American Book Company, 1951
Buku Klasik
Kenny, Anthony
Oxford University Press, 2008
Buku Teks
Hoffding, Harold, author
Dover, 1955
Buku Teks
Bertens, K. (Kees), author
Daras, 2005
Buku Teks