@article{MZM_1973_13_4_a15, author = {S. S. Marchenkov}, title = {Existence of families without positive numerations}, journal = {Matemati\v{c}eskie zametki}, pages = {597--604}, publisher = {mathdoc}, volume = {13}, number = {4}, year = {1973}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/MZM_1973_13_4_a15/} }