Lasnik, Howard, author
Blackwell , 1999
Buku Teks
Radford, Andrew, author
Cambridge University Press, 2003
eBooks
Radford, Andrew, author
Cambridge University Press, 1997
eBooks
Radford, Andrew, author
Cambridge University Press, 2009
eBooks
Gert Webelhuth edited by
Blackwell, 1995
Buku Teks