Infold, Tim, 1948, author
Routledge, 2013
Buku Teks
Newton, Charles Thomas, author
Cambridge University Press, 2011
eBooks
Rodley, Lyn, author
Cambridge University Press, 1999
Buku Teks
edited by George Ansell, Markus Hattstein, Peter Delius
H.F. Ullmann, 2010
Buku Referensi
edited by Markus Hattstein, Peter Delius
Konemann, 2000
Buku Referensi