@article{INTG_1975_7_a16,
     author = {G. G. Ivanov},
     title = {An isotropic gravitational field},
     journal = {Itogi Nauki i Tekhniki. Seriya Problemy Geometrii. Trudy Geometricheskogo Seminara},
     pages = {279--299},
     publisher = {mathdoc},
     volume = {7},
     year = {1975},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/INTG_1975_7_a16/}
}