Sauvain, Philip
Stanley Thornes, 1994
Buku Teks
edited by Peter Taylor-Gooby
Oxford University Press, 2013
Buku Teks
John Doling, Roziah Omar
Ashgate, 2000
Buku Teks
Oxford University Press, 1979
Buku Teks
Titmuss, Richard M.
University of Toronto Press , 1962
Buku Teks