@article{TMF_1996_107_2_a3,
     author = {I. N. Nikitin},
     title = {Quantum string theory in indefinite space of states},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {213--228},
     publisher = {mathdoc},
     volume = {107},
     number = {2},
     year = {1996},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1996_107_2_a3/}
}