Titmuss, Richard M
Longmans Green and Co, 1950
Buku Teks
Stein, Theodore J., author
Columbia University Press, 2001
Buku Teks
edited and introduced by Andrew Shonfield and Stella Shaw
Heinemann Educational Books, 1972
Buku Teks
Clarendon Press Oxford, 1989
Buku Teks
edited by Peter Dwyer, Sandra M I Shaw
Sage, 2013
Buku Teks