@article{TMF_1970_5_1_a0,
     author = {V. A. Kiperman},
     title = {Criterion for a~certain canonical {Fermi} transformation to be proper},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {3--9},
     publisher = {mathdoc},
     volume = {5},
     number = {1},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1970_5_1_a0/}
}