@article{PFMT_2017_2_a0,
     author = {N. A. Akhramenko},
     title = {Gravitational defect of massive ball},
     journal = {Problemy fiziki, matematiki i tehniki},
     pages = {7--9},
     publisher = {mathdoc},
     number = {2},
     year = {2017},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/PFMT_2017_2_a0/}
}