@article{DAN_1982_265_2_a5, author = {N. V. Ivanov}, title = {Entropy and {Nielsen} numbers}, journal = {Doklady Akademii Nauk}, pages = {284--287}, publisher = {mathdoc}, volume = {265}, number = {2}, year = {1982}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1982_265_2_a5/} }