@article{AL_1979_18_2_a1,
     author = {N. T. Vorobev},
     title = {Maximal screens of local formations},
     journal = {Algebra i logika},
     pages = {137--161},
     publisher = {mathdoc},
     volume = {18},
     number = {2},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1979_18_2_a1/}
}