@article{VMUMM_1992_1_a5,
     author = {L. B. Shapiro},
     title = {Extension operators for functions and normal functors},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {35--42},
     year = {1992},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1992_1_a5/}
}