@article{CM_1972__25_1_71_0, author = {Helfenstein, H. G. and Katz, E.}, title = {Intermediate flexibility of surfaces}, journal = {Compositio Mathematica}, volume = {25}, year = {1972}, pages = {71-78}, mrnumber = {320962}, zbl = {0237.53047}, language = {en}, url = {http://dml.mathdoc.fr/item/CM_1972__25_1_71_0} }
Helfenstein, H. G.; Katz, E. Intermediate flexibility of surfaces. Compositio Mathematica, Tome 25 (1972) pp. 71-78. http://gdmltest.u-ga.fr/item/CM_1972__25_1_71_0/
Flächenverbiegung im Grossen, Berlin 1957.
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[2]