@article{RMC_2000_2000_1_a19,
     author = {Cholewa, Jan W. and Dlotko, Tomasz},
     title = {Observaciones sobre las potencias de los operadores el{\'\i}pticos.},
     journal = {Revista matem\'atica complutense},
     pages = {325-336},
     publisher = {mathdoc},
     volume = {13},
     number = {2},
     year = {2000},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RMC_2000_2000_1_a19/}
}