@article{TMF_1998_114_3_a4,
     author = {S. V. Klimenko and I. N. Nikitin},
     title = {Singularities on world sheets of open relativistic strings},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {380--398},
     publisher = {mathdoc},
     volume = {114},
     number = {3},
     year = {1998},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1998_114_3_a4/}
}