@article{ZNSL_1991_198_a9,
     author = {V. M. Tsvetkov},
     title = {$\Gamma$-extentions and homomorphism of corestriction},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {103--108},
     year = {1991},
     volume = {198},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1991_198_a9/}
}