@article{DAN_1967_172_1_a0,
     author = {Yu. Ya. Breitbart},
     title = {Essential variables of functions of the algebra of logic},
     journal = {Doklady Akademii Nauk},
     pages = {9--10},
     publisher = {mathdoc},
     volume = {172},
     number = {1},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1967_172_1_a0/}
}