Olson, James Stuart, 1946-, author
Wiley Blackwell, 2014
Buku Teks
Higgins, Hugh, author
Heinemann Educational, 1975
Buku Teks
Falci, Eric, author
Cambridge University Press, 2015
Buku Teks
edited by Deirdre Osborne
Cambridge University Press, 2016
Buku Teks
Wener, David
California : The hesperian foundation , 19888
Buku Teks