http://www.street.or.jp/divers/ono/umiushi3/ushi3-12.htm
http://www.sea-slug.com/species/umiusi025.htm
http://rfbolland.com/okislugs/bert_sp1.html
http://rfbolland.com/okislugs/bertsp1b.html
http://rfbolland.com/okislugs/bert_sp2.html
http://www.seaslugsofhawaii.com/species/Berthella-sp1-a.html
http://www.nudipixel.net/species/berthella_sp/
http://www.umiushi-zukan.com/eng/list_pic.php?ssw=g&kind_id=1181
http://www.vibrantsea.net/berthella6010_anilao2017.htm
https://www.Philippine-Sea-Slugs.com/Pleurobranchomorpha/Berthella_sp_01.htm
http://www.medslugs.de/E/Pac-W/Berthella_sp_01/Selection.htm