@article{AL_2021_60_4_a3,
     author = {S. A. Badaev and B. S. Kalmurzaev and N. K. Mukash and M. Mustafa},
     title = {One-element rogers semilattices in the {Ershov} hierarchy},
     journal = {Algebra i logika},
     pages = {433--437},
     publisher = {mathdoc},
     volume = {60},
     number = {4},
     year = {2021},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_2021_60_4_a3/}
}