@article{CTGDC_1968__10_3_351_0,
     author = {Legrand, S.},
     title = {Transformations naturelles g\'en\'eralis\'ees},
     journal = {Cahiers de topologie et g\'eom\'etrie diff\'erentielle},
     pages = {351--374},
     publisher = {Dunod \'editeur, publi\'e avec le concours du CNRS},
     volume = {10},
     number = {3},
     year = {1968},
     mrnumber = {257176},
     zbl = {0194.32802},
     language = {fr},
     url = {http://archive.numdam.org/item/CTGDC_1968__10_3_351_0/}
}