@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/
[1] Flächenverbiegung im Grossen, Berlin 1957.
[2] The mathematical theory of rigid surfaces, Lecture notes, University of North Carolina, 1954.