Kunkel, Wolfgang
Clarendon, 1975
Buku Teks SO
Tellegen-Couperus, Olga
Routledge, 1993
Buku Teks SO
Fogg, Gordon Elliott, 1919-
Cambridge Universitry Press, 1992
Buku Teks SO
edited by R.C. Olby, G.N. Cantor, J.R.R. Christie and M.J.S. Hodge
Routledge, 1990
Buku Referensi
edited by W.F. Bynum, E.J. Browne, Roy Porter
Macmillan Reference Books, 1989
Buku Referensi