@article{INTF_1988_34_a2,
     author = {V. M. Babich},
     title = {The multidimensional {WKB} method or the ray method. {Its} analogues and generalizations},
     journal = {Itogi Nauki i Tekhniki. Seriya Sovremennye Problemy Matematiki. Fundamental'nye Napravleniya},
     pages = {93--134},
     year = {1988},
     volume = {34},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/INTF_1988_34_a2/}
}