@unpublished{GalstianYagdjian1997,
  author    = {Galstian, Anahit and Yagdjian, Karen},
  title     = {Exponential function of pseudo-differential operators},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-24982},
  year      = {1997},
  abstract  = {The paper is devoted to the construction of the exponential function of a matrix pseudo-differential operator which do not satisfy any of the known theorems (see, Sec.8 Ch.VIII and Sec.2 Ch.XI of [17]). The applications to the construction of the fundamental solution for the Cauchy problem for the hyperbolic operators with the characteristics of variable multiplicity are given, too.},
  language  = {en}
}