http://rfbolland.com/okislugs/bullline.html
http://www.uow.edu.au/science/research/affrc/shellcove/bullina.html
http://www.seaslugforum.net/factsheet.cfm?base=bullline
http://www.umiushi.info/photo_species/photo_splist_eng.php?sopt=0&loc=0000
http://www.medslugs.de/E/Pac-NW/Bullina_lineata.htm
http://seaslugs.free.fr/nudibranche/a_bulli_lineata.htm
http://gastropods.com/9/Shell_4029.shtml
http://www.seaslugsofhawaii.com/species/Bullina-lineata-a.html
http://www.underwaterkwaj.com/nudi/hawaii/hc03.htm