http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=11&cad=rja&ved=0CD0QFjAAOAo&url=http%3A%2F%2Fwww.societyofrobots.com%2Fsensors_forcetorque.shtml&ei=6JdkUMPkMsbM2AXQ04GoAg&usg=AFQjCNFgFa4hWocLrnCBzYcnWAfn_dvBXw
http://www.dlr.de/rm/en/desktopdefault.aspx/tabid-3806/6231_read-8995/
http://www.stellartech.com/products/techsheets-load/loadmodels.html