http://slugsite.us/bow/nudiwkps/nudiwk11.html
http://divegallery.com/nudi15pa.htm
http://www.seaslugforum.net/showall/halgwill
http://www.angelfire.com/mi/sharkcage69/nudi/hal1.html
http://www.diveoz.com.au/nudibranchs/gallery/display_nudibranch.asp?nudi=56
http://rfbolland.com/okislugs/halgwill.html
http://rfbolland.com/okislugs/halgwil2.html
http://www.subaqua.ch/sib033e.htm
http://www.medslugs.de/E/Pac-W/Halgerda_willeyi/Selection.htm
http://www.cosmos.ne.jp/~breach/slug%20full%203/nudi%20full69.html
http://www.cosmos.ne.jp/~breach/slug%20full%204/nudi%20full115.html
http://www2.gateway.ne.jp/~coon/slug-54.htm
http://www.umiushi.info/photo_species/photo_splist_eng.php?sopt=0&loc=0000
http://www.Philippine-Sea-Slugs.com/Nudibranchia/Euctenidiacea/Halgerda_willeyi.htm
http://www.medslugs.de/E/Pac-NW/Halgerda_willeyi/Selection.htm
http://www.vibrantsea.net/halgerda1_anilao11.htm
http://www.vibrantsea.net/halgerda6_anilao23.htm
http://slugsite.us/bow/nudwk502.htm
http://www.medslugs.de/E/Ind-NW/Halgerda_willeyi/Selection.htm
http://www.nudibranch.com.au/pages/4991a.htm
http://www.scuba-equipment-usa.com/marine/JUN05/Willeys_Halgerda(Halgerda_willeyi).html
http://ianskipworth.com/suig/nudis.html
http://www.medslugs.de/E/Pac-SW/Halgerda_willeyi/Selection.htm
http://www.nudibranch.org/Philippine Sea Slugs/html/nudibranchs/halgerda-willeyi-01.html
http://www.nudipixel.net/species/halgerda_willeyi/
http://tahitinudi.jimdo.com/liste-des-espèces/halgerda-willeyi/
http://www.umiushi-zukan.com/eng/list_pic.php?ssw=g&kind_id=244
http://www.dragonmouse.com.au/diving/nudibase.php?action=nudidetail&id=230
http://www.medslugs.de/E/Ind-E/Halgerda_willeyi/Selection.htm