(en) Peter Harrison, Castles of God : Fortified Religious Buildings of the World, Boydell Press, , 304 p. (ISBN1-84383-066-3, lire en ligne), p. 268–270
(en) Colin Monteath, Climb Every Mountain : A Journey to the Earths Most Spectacular High Altitude Locations, Frances Lincoln ltd, , 232 p. (ISBN0-7112-2674-1, lire en ligne), p. 118–119