Jacobs, Kristof, author
Palgrave Macmillan, 2016
Buku Teks
Barton, Jonathan R.
Routledge, 1997
Buku Teks
Scott, Andrew M., author
Holt, Rinehart & Winston, 1959
Buku Teks
edited by Philip John Davies and Fredric A. Waldstein
Manchester University Press, 1987
Buku Teks
Booth, John A., author
Westerview Press, 1993
Buku Teks