@article{RSMUP_1977__58__191_0,
     author = {Bratti, Giuliano},
     title = {A remark about elliptic overdeterminated systems},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {191--194},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {58},
     year = {1977},
     mrnumber = {543140},
     zbl = {0411.35020},
     language = {en},
     url = {http://archive.numdam.org/item/RSMUP_1977__58__191_0/}
}