Doomtrooper Official Website

Features card lists, strategy, and information on homemade expansion sets.
http://www.thewinternet.com/doomtrooper/

Globetrotter Games

Offers rules of the game.
http://globetrotter-games.com/index.htm?E&game/eDoomTr.htm

Doomtrooper

Spoilers and Cardlists, FAQs, and rules.
http://www.geocities.com/Area51/Vault/4587/trooper.htm