@article{KUTGS_1986_17_a6,
     author = {N. D. Petsko},
     title = {Twistor geometry},
     journal = {Trudy Geometricheskogo Seminara},
     pages = {53--60},
     year = {1986},
     volume = {17},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/KUTGS_1986_17_a6/}
}