@article{30586, author = "Ballarin, S. and XII Assemblée Génerale de l'UGGI a Helsinki, 1960", title = "The squared maps for medium altitudes of Italy an the limitroph districts, and maps of equal medium cote lines employed for the reduction of gravity measures executed for the construction of the Italian gravimetric map ", year = "1960", note = "1 sv., 4 vol. map. příl., Italian Geodetic Commission", }