@article{JEDP_1984____A10_0,
     author = {Beals, Michael},
     title = {Semilinear wave equations with angularly smooth data},
     journal = {Journ\'ees \'equations aux d\'eriv\'ees partielles},
     eid = {10},
     pages = {1--5},
     publisher = {Ecole polytechnique},
     year = {1984},
     zbl = {0614.35058},
     language = {en},
     url = {http://www.numdam.org/item/JEDP_1984____A10_0/}
}