@article{10_2298_BMAT0227057P,
     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 },
     publisher = {mathdoc},
     volume = {27},
     year = {2002},
     doi = {10.2298/BMAT0227057P},
     zbl = {1219.47068},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.2298/BMAT0227057P/}
}