@article{SE_1957-1958__1__A6_0,
     author = {Willmore, T. J.},
     title = {Generalized torsional derivation},
     journal = {S\'eminaire de topologie et g\'eom\'etrie diff\'erentielle},
     note = {talk:17},
     pages = {1--12},
     publisher = {Secr\'etariat math\'ematique},
     volume = {1},
     year = {1957-1958},
     mrnumber = {121730},
     zbl = {0134.39801},
     language = {en},
     url = {http://www.numdam.org/item/SE_1957-1958__1__A6_0/}
}