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@article{MAN_1869__1_156425, author = {E. Beltrami}, title = {Zur {Theorie} des {Kr\"ummungsmaasses,} {Von} {E.} {Beltrami} in {Bologna.}}, journal = {Mathematische Annalen}, pages = {575--582}, publisher = {mathdoc}, volume = {1}, year = {1869}, language = {de}, url = {http://geodesic.mathdoc.fr/item/MAN_1869__1_156425/} }
E. Beltrami. Zur Theorie des Krümmungsmaasses, Von E. Beltrami in Bologna.. Mathematische Annalen, Tome 1 (1869), pp. 575-582. http://geodesic.mathdoc.fr/item/MAN_1869__1_156425/