@article{DAN_1980_252_1_a6,
     author = {V. R. Kireitov},
     title = {On photometric quantities on a {Riemannian} manifold},
     journal = {Doklady Akademii Nauk},
     pages = {27--33},
     publisher = {mathdoc},
     volume = {252},
     number = {1},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_252_1_a6/}
}