@article{DAN_1970_193_3_a5,
     author = {Z. I. Kozlova},
     title = {An $R$-operation with complete depth of chains over systems of sets of power~$\tau$},
     journal = {Doklady Akademii Nauk},
     pages = {521--524},
     publisher = {mathdoc},
     volume = {193},
     number = {3},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1970_193_3_a5/}
}