Palmer, Donald, author
McGraw-Hill, 2001
Buku Teks
edited by Dagobert D. Runes
Littlefield, Adams & Co., 1959
Buku Referensi
Ayer, A. J. (Alfred Jules), 1910-1989, author
Penguin Books, 1982
Buku Teks
Baggini, Julian, author
Palgrave Macmillan, 2012
Buku Teks
edited by Nicholas Bunnin and E. P. Tsui-James
Wiley, 2003
Buku Teks