@article{UZKU_1952_112_10_a3,
     author = {A. Z. Petrov},
     title = {Gravitational fields with complex stationary curvatures},
     journal = {U\v{c}\"enye zapiski Kazanskogo universiteta. Seri\^a Fiziko-matemati\v{c}eskie nauki},
     pages = {35--47},
     publisher = {mathdoc},
     volume = {112},
     number = {10},
     year = {1952},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/UZKU_1952_112_10_a3/}
}