Val des Dix, Stollenbau Grande Dixence

<em>Gerber, Hans: Val des Dix, Stollenbau Grande Dixence, 1955 (Com_M04-0426-0009, <a href="http://doi.org/10.3932/ethz-a-000658361">http://doi.org/10.3932/ethz-a-000658361</a>)