Oxford University Press, 1979
Buku Teks
Malecki, Edward J.
Longman Scientific & Technical, 1991
Buku Teks
edited by Anne Hellum, Henriette Sinding Aasen
Cambridge University Press, 2013
Buku Teks
Jayawickrama, Nihal
Cambridge University Press, 2017
eBooks
Langley, Anne
Chandos Publishing, 2006
Buku Teks