@incollection{JEDP_1991____A9_0,
     author = {Melin, Anders},
     title = {Inverse problems and microlocal analysis},
     booktitle = {},
     series = {Journ\'ees \'equations aux d\'eriv\'ees partielles},
     eid = {9},
     pages = {1--7},
     publisher = {Ecole polytechnique},
     year = {1991},
     mrnumber = {1132230},
     zbl = {0738.35053},
     language = {en},
     url = {http://archive.numdam.org/item/JEDP_1991____A9_0/}
}