@article{DAN_1973_213_2_a16,
     author = {E. S. Ratner and Yu. Z. Matskovskaya},
     title = {On the connection between threshold contrast and the object form},
     journal = {Doklady Akademii Nauk},
     pages = {313--314},
     publisher = {mathdoc},
     volume = {213},
     number = {2},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1973_213_2_a16/}
}