@incollection{JEDP_1990____A20_0,
     author = {Klopp, Fr\'ed\'eric},
     title = {Impuret\'es dans une structure p\'eriodique},
     booktitle = {},
     series = {Journ\'ees \'equations aux d\'eriv\'ees partielles},
     eid = {20},
     pages = {1--12},
     year = {1990},
     publisher = {Ecole polytechnique},
     doi = {10.5802/jedp.402},
     zbl = {0707.35125},
     mrnumber = {91k:35184},
     language = {fr},
     url = {https://www.numdam.org/articles/10.5802/jedp.402/}
}