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@article{DAN_1963_148_4_a7, author = {V. A. Matulis}, title = {Variants of the classical predicate calculus with a unique tree of deduction}, journal = {Doklady Akademii Nauk}, pages = {768--770}, publisher = {mathdoc}, volume = {148}, number = {4}, year = {1963}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1963_148_4_a7/} }
V. A. Matulis. Variants of the classical predicate calculus with a unique tree of deduction. Doklady Akademii Nauk, Tome 148 (1963) no. 4, pp. 768-770. http://geodesic.mathdoc.fr/item/DAN_1963_148_4_a7/