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@article{IVM_1969_10_a11, author = {L. L. Tsinman}, title = {A~theorem on normal proofs in the theory of regular formulae}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {90--96}, publisher = {mathdoc}, number = {10}, year = {1969}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1969_10_a11/} }
L. L. Tsinman. A~theorem on normal proofs in the theory of regular formulae. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 10 (1969), pp. 90-96. http://geodesic.mathdoc.fr/item/IVM_1969_10_a11/