@article{VMUMM_2006_1_a9,
     author = {N. V. Krupskii},
     title = {Minimal models and the complexity of fragments of the logic of proofs},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {52--53},
     publisher = {mathdoc},
     number = {1},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2006_1_a9/}
}