@article{DA_1995_2_2_a4,
     author = {I. Mirchev},
     title = {Strongly essential variables of functions of $k$-valued logic},
     journal = {Diskretnyj analiz i issledovanie operacij},
     pages = {62--68},
     publisher = {mathdoc},
     volume = {2},
     number = {2},
     year = {1995},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DA_1995_2_2_a4/}
}