Robson, L.L., author
Cambridge University Press, 1976
Buku Teks
Hasluck, Alexandra
Angus and Robertson, 1969
Buku Teks
Ekirch, A. Roger
Cloarendon Press, 1987
Buku Teks
Cambridge University Press, 1989
Buku Teks
O`Brien, Eris, author
Angus & Robertson , 1950
Buku Teks