@article{MZM_1970_8_1_a8,
     author = {O. I. Bogoyavlenskii},
     title = {Exact functions on manifolds},
     journal = {Matemati\v{c}eskie zametki},
     pages = {77--83},
     publisher = {mathdoc},
     volume = {8},
     number = {1},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1970_8_1_a8/}
}