Artificial caves as a possible danger_ sinkholes and other effects at the surface
Parise M., 2012, Artificial caves as a possible danger_ sinkholes and other effects at the surface,
International Workshop on Speleology in Artificial Cavities "Classification of the typologies of artificial cavities in the world", pp. 12–12, Torino (Italy), 18-20 May 2012,
URL: http://www.cnr.it/prodotto/i/192291
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