@article{IM2_1992_38_1_a5,
     author = {S. Z. Levendorskii},
     title = {An algebra of boundary value problems for a class of pseudodifferential operators of variable order},
     journal = {Izvestiya. Mathematics },
     pages = {131--154},
     publisher = {mathdoc},
     volume = {38},
     number = {1},
     year = {1992},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1992_38_1_a5/}
}