@article{TMF_1973_15_1_a11,
     author = {Yu. M. Zinoviev},
     title = {On group extensions connected with the {Poincar\'e} group},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {139--141},
     publisher = {mathdoc},
     volume = {15},
     number = {1},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1973_15_1_a11/}
}