@incollection{JEDP_1989____A20_0,
     author = {Xu, Chaojiang},
     title = {Propagation de la r\'egularit\'e microlocale pour des probl\`emes de {Dirichlet} non lin\'eaires d'ordre deux},
     booktitle = {},
     series = {Journ\'ees \'equations aux d\'eriv\'ees partielles},
     eid = {20},
     pages = {1--8},
     publisher = {Ecole polytechnique},
     year = {1989},
     mrnumber = {90m:35135},
     zbl = {0726.35026},
     language = {fr},
     url = {http://archive.numdam.org/item/JEDP_1989____A20_0/}
}