@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}, publisher = {Ecole polytechnique}, year = {1981}, zbl = {0492.32024}, language = {en}, url = {http://www.numdam.org/item/JEDP_1981____A8_0/} }