@article{DM_2009_21_3_a4,
     author = {S. S. Marchenkov},
     title = {Positively closed classes of three-valued logic generated by one-place functions},
     journal = {Diskretnaya Matematika},
     pages = {37--44},
     publisher = {mathdoc},
     volume = {21},
     number = {3},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_2009_21_3_a4/}
}