Axe websites with useful information:
Fur Trade Axes and Tomahawks - www.furtradetomahawks.com
Trade Axes and Tomahawk Collectors Association - tatcalite.tripod.com/index.htm
An article on Boarding Axes by Sa’ar Nudel - https://www.academia.edu/24018133/The_Boarding_Axe
Antique weapon forums:
Ethnographic Arms and Armour Forum - www.vikingsword.com
Sword Forum International - www.swordforum.com