@article{AIF_1978__28_2_221_0,
     author = {Helffer, Bernard},
     title = {Addition de variables et application \`a la r\'egularit\'e},
     journal = {Annales de l'Institut Fourier},
     pages = {221--231},
     publisher = {Institut Fourier},
     address = {Grenoble},
     volume = {28},
     number = {2},
     year = {1978},
     doi = {10.5802/aif.697},
     mrnumber = {58 #1566},
     zbl = {0365.35012},
     language = {fr},
     url = {http://www.numdam.org/articles/10.5802/aif.697/}
}