@article{TM_1972_121_a3,
     author = {S. Yu. Maslov and V. P. Orevkov},
     title = {Decidable classes that reduce to a single quantifier class},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {57--66},
     publisher = {mathdoc},
     volume = {121},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1972_121_a3/}
}