@article{DAN_1985_285_4_a0,
     author = {K. I. Babenko},
     title = {The maximum principle for the {Euler{\textendash}Tricomi} equation},
     journal = {Doklady Akademii Nauk},
     pages = {777--782},
     year = {1985},
     volume = {285},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1985_285_4_a0/}
}