@article{MZM_2001_70_5_a12,
     author = {V. I. Ovchinnikov and A. S. Titenkov},
     title = {A {Criterion} for {Contiguity} of {Quasiconcave} {Functions}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {780--786},
     publisher = {mathdoc},
     volume = {70},
     number = {5},
     year = {2001},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2001_70_5_a12/}
}