edited by Stanley Cramp, C.M. Perrins
Oxford University Press, 1993
Buku Referensi
Weber, Eugen
D.C. Heath, 1959
Buku Teks SO
Burns, Edward McNall, 1897-1972
W.W Norton, 1980
Buku Teks
Easton, Stewart C.
Holt, Rinehart and Winston, 1966
Buku Teks SO
Sutton, Ian
TThames & Hudson, 2001
Buku Teks SO