@article{RSMUP_1935__6__21_0,
     author = {Nikodym, Otton},
     title = {Quelques observations sur les int\'egrales g\'en\'erales des \'equations diff\'erentielles},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {6},
     year = {1935},
     pages = {21-43},
     zbl = {0012.06701},
     language = {fr},
     url = {http://www.numdam.org/item/RSMUP_1935__6__21_0}
}

Nikodym, Otton. Quelques observations sur les intégrales générales des équations différentielles. Rendiconti del Seminario Matematico della Università di Padova, Tome 6 (1935) pp. 21-43. https://www.numdam.org/item/RSMUP_1935__6__21_0/