Fielding, Helen
Picador, 1997
Buku Teks
Mettem, Christopher J.
Spon Press, 2011
Buku Teks
Wells, Matthew
Watson-Guptill Publications, 2002
Buku Teks
Connelly, Bridget
University Press, 1986
Buku Teks
editors, Rui Calcada, Raimundo Delgado, Antonio Campos e Matos
CRC Press, Taylor & Francis Group, 2009
Buku Teks