@article{DAN_1979_245_4_a15, author = {L. A. Ivanov}, title = {Huygens principle for equations dissociating into factors}, journal = {Doklady Akademii Nauk}, pages = {829--832}, publisher = {mathdoc}, volume = {245}, number = {4}, year = {1979}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1979_245_4_a15/} }