Toward the description in a smooth topos of the dynamically possible motions and deformations of a continuous body
Cahiers de Topologie et Géométrie Différentielle Catégoriques, Volume 21 (1980) no. 4, p. 377-392 
@article{CTGDC_1980__21_4_377_0,
     author = {Lawvere, F. William},
     title = {Toward the description in a smooth topos of the dynamically possible motions and deformations of a continuous body},
     journal = {Cahiers de Topologie et G\'eom\'etrie Diff\'erentielle Cat\'egoriques},
     publisher = {Dunod \'editeur, publi\'e avec le concours du CNRS},
     volume = {21},
     number = {4},
     year = {1980},
     pages = {377-392},
     zbl = {0472.18009},
     mrnumber = {606383},
     language = {en},
     url = {http://www.numdam.org/item/CTGDC_1980__21_4_377_0}
}

Lawvere, F. William. Toward the description in a smooth topos of the dynamically possible motions and deformations of a continuous body. Cahiers de Topologie et Géométrie Différentielle Catégoriques, Volume 21 (1980) no. 4, pp. 377-392. http://www.numdam.org/item/CTGDC_1980__21_4_377_0/