@article{MZM_1991_50_4_a8,
     author = {A. N. Degtev},
     title = {The semilattice of computable families of recursively enumerable sets},
     journal = {Matemati\v{c}eskie zametki},
     pages = {61--66},
     publisher = {mathdoc},
     volume = {50},
     number = {4},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1991_50_4_a8/}
}