@incollection{JEDP_1981____A8_0,
     author = {Tr\`eves, Fran\c{c}ois},
     title = {Non embeddable {CR-structures}},
     booktitle = {},
     series = {Journ\'ees \'equations aux d\'eriv\'ees partielles},
     eid = {8},
     pages = {1--8},
     year = {1981},
     publisher = {Ecole polytechnique},
     doi = {10.5802/jedp.231},
     zbl = {0492.32024},
     language = {en},
     url = {https://www.numdam.org/articles/10.5802/jedp.231/}
}