Bender, David L.
Grennhaven Press, 1981
Buku Teks SO
edited by P.M.S. Hacker and J. Raz
Clarendon Press, 1988
Buku Teks SO
edited by T.E. Hall, P.R. Jones, G.B. Preston
Academic Press, 1980
Buku Teks SO
Sergeant, Graham
Macmillan, 1973
Buku Teks SO
Cowen, Zelman
Butteworths, 1983
Buku Teks SO