@article{MVK_2015_6_1_a3,
     author = {V. S. Litvinenko and A. V. Tarasov},
     title = {Schaefer classes, {Post} classes and {Galois} connections},
     journal = {Matemati\v{c}eskie voprosy kriptografii},
     pages = {81--107},
     year = {2015},
     volume = {6},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MVK_2015_6_1_a3/}
}