Dimitris Ballas, Graham Clarke, Rachel S. Franklin and Andy Newing, authors
Routledge, Taylor & Francis Group, 2018
Buku Teks
editor, Herbert H.P. Fang
Imperial College Press, 2010
Buku Teks
Owen, Claudia
Brooks/Cole Cengage Learning, 2010
Buku Teks
New York : macmillan Library reference USA, 1997,
Buku Referensi
edited by Andrew Skidmore
Taylor and Francis, 2002
Buku Teks