White, N.D.
Manchester University Press, 1993
Buku Teks
edited by Robin Higham
University of Kentucky Press, 1972
Buku Teks
Kirgis, Frederic L.
West Publishing, 1993
Buku Teks
edited by Evan Luard
Praeger, 1966
Buku Teks
Edwards, Paul M.
Paul M. Edwards, 2006
Buku Referensi