@article{SEDP_1970-1971____A1_0,
     author = {Oleinik, O. A.},
     title = {Hypoellipticit\'e et r\'egularit\'e locale des solutions faibles des \'equations aux d\'eriv\'ees partielles du second ordre},
     journal = {S\'eminaire \'Equations aux d\'eriv\'ees partielles (Polytechnique) dit aussi "S\'eminaire Goulaouic-Schwartz"},
     note = {talk:1},
     pages = {1--15},
     publisher = {Ecole Polytechnique, Centre de Math\'ematiques},
     year = {1970-1971},
     mrnumber = {415057},
     zbl = {0252.35016},
     language = {fr},
     url = {http://archive.numdam.org/item/SEDP_1970-1971____A1_0/}
}