Thomason, John
Crowood, 1995
Buku Teks
Laarhove, Ruurdje
New Day Publisher, 1989
Buku Teks
Geoffrey Till, Patrick C. Bratton, editors
Routledge, 2012
Buku Teks
Brown, Peter, 1935-, author
Wiley-Blackwell, 2013
Buku Teks
Holiday, Ryan, author
Penguin, 2014
Buku Teks