@article{RM_1969_24_1_a6,
     author = {M. S. Agranovich},
     title = {Boundary value problrms for systems of first order pseudodifferential operators},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {59--126},
     publisher = {mathdoc},
     volume = {24},
     number = {1},
     year = {1969},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1969_24_1_a6/}
}