@article{DAN_1973_208_6_a17,
     author = {R. F. Polishchuk},
     title = {Isometries of {Pfaff's} space -- time systems},
     journal = {Doklady Akademii Nauk},
     pages = {1321--1324},
     publisher = {mathdoc},
     volume = {208},
     number = {6},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1973_208_6_a17/}
}