@article{MZM_1984_35_5_a4,
     author = {S. A. Gurchenkov},
     title = {Coverings in the lattice $l$-varieties},
     journal = {Matemati\v{c}eskie zametki},
     pages = {677--684},
     publisher = {mathdoc},
     volume = {35},
     number = {5},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1984_35_5_a4/}
}