@article{RSMUP_2001__105__215_0, author = {Nicola, F.}, title = {Weyl formula for quasi-elliptic pseudo-differential operators}, journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova}, pages = {215--231}, publisher = {Seminario Matematico of the University of Padua}, volume = {105}, year = {2001}, mrnumber = {1834992}, zbl = {1072.58018}, language = {en}, url = {http://www.numdam.org/item/RSMUP_2001__105__215_0/} }