http://www.seaslugforum.net/factsheet.cfm?base=eubrcfrubr
http://www.ne.jp/asahi/kappa-kuri/miyamoto/OSEHOO/umiushi276.html
http://www.h.do-up.com/home/takayan/takapage476.htm
http://slugsite.us/bow2007/nudwk560.htm