http://citation.dbpedia.org/hash2/ecf66850fc725c269164fca856ceafb823556013a2a54234a4a28e5b70f7747d
817
http://books.google.com/books?vid=ISBN9781905625161
6
http://books.google.com/books?vid=ISBN0947766146
1
http://books.google.com/books?vid=ISBN0356102394
1