@incollection{JEDP_1981____A5_0, author = {Stein, Elias M.}, title = {Compositions of pseudo-differential operators}, booktitle = {}, series = {Journ\'ees \'equations aux d\'eriv\'ees partielles}, eid = {5}, pages = {1--6}, publisher = {Ecole polytechnique}, year = {1981}, language = {en}, url = {http://www.numdam.org/item/JEDP_1981____A5_0/} }