Downes, Colm, author
Cambridge university press, 2009
Buku Teks
Ceramella, Nick, author
Cambridge university press, 2011
Buku Teks
Ibbotson, Mark, author
Cambridge university press, 2010
Buku Teks
David L. Sam; John W. Berry, editor
Cambridge University Press, 2006
Buku Teks
Mee, Jon, author
Cambridge University Press , 2010
Buku Teks