http://www.medslugs.de/E/Med/Berthella_ocellata.htm
http://www.marenostrum.org/opistobranquios/bocellata/bocellat.htm
http://www.seaslugforum.net/showall/bertocel
http://www.ugr.es/~lstocino/berthella_ocellata.htm
http://www.medslugs.de/E/Atl-E/Berthella_ocellata.htm
http://www.nembro.info/uk_berthella_ocellata.html
http://opistobranquis.info/en/guia/pleurobranchomorpha/berthella-ocellata/