Ronan Paddison, Tom Hutton, editors
Sage, 2015
Buku Teks
Tate, Alan, author
Spon Press, 2001
Buku Teks
Sage Publications, 1989
Buku Teks
edited by Stanley Cramp, C.M. Perrins
Oxford University Press, 1993
Buku Referensi
Stanford Univesity Press, 1978
Buku Teks