@incollection{JEDP_1981____A3_0, author = {Kohn, J. J.}, title = {Subelliptic estimates}, booktitle = {}, series = {Journ\'ees \'equations aux d\'eriv\'ees partielles}, eid = {3}, pages = {1--7}, publisher = {Ecole polytechnique}, year = {1981}, zbl = {0487.35037}, language = {en}, url = {http://www.numdam.org/item/JEDP_1981____A3_0/} }