@article{IVM_1987_2_a4,
     author = {A. A. Grigor'yan},
     title = {On the set of positive solutions of the {Laplace--Beltrami} equation on {Riemannian} manifolds of a~special form},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {30--37},
     publisher = {mathdoc},
     number = {2},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1987_2_a4/}
}