@article{INTG_1984_16_a0,
     author = {Yu. V. Pavlyuchenko and V. V. Ryzhkov},
     title = {Bending of point correspondences. $\omega$-systems},
     journal = {Itogi Nauki i Tekhniki. Seriya Problemy Geometrii. Trudy Geometricheskogo Seminara},
     pages = {3--34},
     year = {1984},
     volume = {16},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/INTG_1984_16_a0/}
}