@article{RSMUP_1976__56__245_0,
     author = {Menegus, Annalisa and Olivi, Giuseppe},
     title = {Partially elliptic pseudodifferential operators and the $WF_x$ of distributions},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {245--255},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {56},
     year = {1976},
     mrnumber = {487124},
     zbl = {0375.35054},
     language = {en},
     url = {http://www.numdam.org/item/RSMUP_1976__56__245_0/}
}