http://slugsite.us/bow/pacific/polyalph.html
http://www.medslugs.de/E/Pac-NE/Navanax_polyalphos/Selection.htm
http://www.seaslugforum.net/showall/navapoly
http://slugsite.us/bow2007/nudwk566.htm
http://www.inbio.ac.cr/papers/babosasmarinas/ingles/listadeesp.htm
http://www.medslugs.de/E/Pac-E/Navanax_polyalphos/Selection.htm
http://scottpenny.smugmug.com/gallery/3881249_R9eMK/5
http://www.nudipixel.net/species/navanax_polyalphos/