@article{JEDP_1981____A8_0,
     author = {Tr\`eves, Fran\c{c}ois},
     title = {Non embeddable {CR-structures}},
     journal = {Journ\'ees \'equations aux d\'eriv\'ees partielles},
     eid = {8},
     pages = {1--8},
     publisher = {Ecole polytechnique},
     year = {1981},
     zbl = {0492.32024},
     language = {en},
     url = {http://www.numdam.org/item/JEDP_1981____A8_0/}
}