@incollection{JEDP_1997____A10_0, author = {Klainerman, S. and Machedon, Matei}, title = {On the regularity properties of non-linear wave equations}, booktitle = {}, series = {Journ\'ees \'equations aux d\'eriv\'ees partielles}, eid = {10}, pages = {1--8}, publisher = {Ecole polytechnique}, year = {1997}, language = {en}, url = {http://archive.numdam.org/item/JEDP_1997____A10_0/} }