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@article{DAN_1976_227_1_a12, author = {M. I. Kratko}, title = {The number of switchings that are necessary for the unblocking of a three-step commutator}, journal = {Doklady Akademii Nauk}, pages = {54--56}, publisher = {mathdoc}, volume = {227}, number = {1}, year = {1976}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1976_227_1_a12/} }
M. I. Kratko. The number of switchings that are necessary for the unblocking of a three-step commutator. Doklady Akademii Nauk, Tome 227 (1976) no. 1, pp. 54-56. http://geodesic.mathdoc.fr/item/DAN_1976_227_1_a12/