@article{DAN_1966_170_6_a2,
     author = {I. A. Zhigulin},
     title = {Certain classes of orbits for the group of triangular-unit matrices},
     journal = {Doklady Akademii Nauk},
     pages = {1247--1250},
     year = {1966},
     volume = {170},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1966_170_6_a2/}
}