@article{UZKU_1970_129_6_a1,
     author = {V. N. Abdullin},
     title = {A classification of the four-dimensional {Riemannian} spaces that admit fields of covariantly constant bivectors},
     journal = {U\v{c}\"enye zapiski Kazanskogo universiteta. Seri\^a Fiziko-matemati\v{c}eskie nauki},
     pages = {5--21},
     publisher = {mathdoc},
     volume = {129},
     number = {6},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/UZKU_1970_129_6_a1/}
}