@article{RSMUP_1980__63__83_0,
     author = {Zampieri, Giuseppe},
     title = {A sufficient condition for existence of real analytic solutions of {P.D.E.} with constant coefficients, in open sets of $\mathbb {R}^2$},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {83--87},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {63},
     year = {1980},
     mrnumber = {605785},
     zbl = {0499.35021},
     language = {en},
     url = {http://www.numdam.org/item/RSMUP_1980__63__83_0/}
}