Oliver, Dawn, author
Pinter, A Cassell Imprint, 1996
Buku Teks
Brown, Esther Lucile, author
Russell Sage Foundation, 1948
Buku Teks
edited by Mark Bovens, Robert E. Goodin and Thomas Schillemans
Oxford University Press, 2014
Buku Teks
Cooper, Phillip J., author
Thomson Wadsworth, 2005
Buku Teks
Hillier, Timothy, author
Cavendish, 1994
Buku Teks