@article{VMUMM_1998_6_a4,
     author = {T. L. Sidon},
     title = {Nonaxiomatizability of predicate logics of proofs},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {18--22},
     publisher = {mathdoc},
     number = {6},
     year = {1998},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1998_6_a4/}
}