@article{KUTGS_1990_20_a7,
     author = {\`E. G. Neifel'd},
     title = {Intrinsic geometries of a normalized {Penrosian}},
     journal = {Trudy Geometricheskogo Seminara},
     pages = {70--73},
     publisher = {mathdoc},
     volume = {20},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/KUTGS_1990_20_a7/}
}