@incollection{JEDP_1995____A16_0,
     author = {Stein, Elias M.},
     title = {Spectral multipliers and multiple-parameter structures on the {Heisenberg} group},
     booktitle = {},
     series = {Journ\'ees \'equations aux d\'eriv\'ees partielles},
     eid = {16},
     pages = {1--15},
     publisher = {Ecole polytechnique},
     year = {1995},
     mrnumber = {96k:22018},
     zbl = {0876.43005},
     language = {en},
     url = {http://archive.numdam.org/item/JEDP_1995____A16_0/}
}