edited by Clement Semmler and Derek Whitelock
F.W. Cheshire, 1966
Buku Teks
Peter Pierce, Rosemary Hunter, editor
Oxford Univeristy Press, 1987
Buku Referensi
general editor: Laurie Hergenhan ; editors : Bruce Bennett ... [et al.]
Penguin Books, 1988
Buku Teks
Crawford, R.M., author
Hutchinson's University Library, 1955
Buku Teks
Crawford, R.M., author
Hutchinson University Library, 1952.
Buku Teks