@article{BASS_2002_27_1_a4,
     author = {S. Pilipovi\'c and N. Teofanov},
     title = {On a symbol class of elliptic pseudodifferential operators},
     journal = {Bulletin de l'Acad\'emie serbe des sciences. Classe des sciences math\'ematiques et naturelles},
     pages = {57 - 68},
     publisher = {mathdoc},
     volume = {27},
     number = {1},
     year = {2002},
     zbl = {1219.47068},
     url = {http://geodesic.mathdoc.fr/item/BASS_2002_27_1_a4/}
}