@article{AIHPC_1991__8_3-4_227_0,
     author = {Lions, Pierre-Louis},
     title = {Introduction},
     journal = {Annales de l'I.H.P. Analyse non lin\'eaire},
     pages = {227--227},
     publisher = {Gauthier-Villars},
     volume = {8},
     number = {3-4},
     year = {1991},
     language = {fr},
     url = {http://www.numdam.org/item/AIHPC_1991__8_3-4_227_0/}
}