@article{DAN_1974_218_3_a8,
     author = {Ya. Z. Tsypkin and B. T. Polyak},
     title = {Attainable accuracy of adaptation algorithms},
     journal = {Doklady Akademii Nauk},
     pages = {532--535},
     publisher = {mathdoc},
     volume = {218},
     number = {3},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1974_218_3_a8/}
}