@article{KUTGS_1991_21_a7,
     author = {G. V. Ivshina},
     title = {Invariants of a four-dimensional {Riemannian} space and their changes under conformal transformation},
     journal = {Trudy Geometricheskogo Seminara},
     pages = {57--63},
     publisher = {mathdoc},
     volume = {21},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/KUTGS_1991_21_a7/}
}