http://www.pictonb.freeserve.co.uk/nudibranchs/dottub.html
http://www.habitas.org.uk/marinelife/species.asp?item=W12890
https://en.wikipedia.org/wiki/Doto_tuberculata
http://www.medslugs.de/E/Atl-NE/Doto_tuberculata/Selection.htm