@article{MZM_1990_47_4_a4,
     author = {S. A. Gurchenkov},
     title = {The lattice of varieties of rigid lattice-ordered groups does not have the covering property},
     journal = {Matemati\v{c}eskie zametki},
     pages = {35--40},
     publisher = {mathdoc},
     volume = {47},
     number = {4},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1990_47_4_a4/}
}