http://www.gulliver.it/cai/cf http://www.guidealpine.lombardia.it http://www.sac-cas.ch/huetten http://www.swiss-sport.ch/sac-cas/huetten http://castore.phys.uniroma1.it/Rifugi.html http://www.worldsport.com/worldsport/sports/mountaineering http://www.princeton.edu/~oa http://www.nols.edu/Publications/FirstAid/FirstAid.html http://www.nols.edu/Publications/MtneeringBook/MtneeringBook.html