@article{MT_2007_10_1_a7,
     author = {Yu. G. Nikonorov},
     title = {On {Einstein} {Extensions} of {Nilpotent} {Metric} {Lie} {Algebras}},
     journal = {Matemati\v{c}eskie trudy},
     pages = {164--190},
     publisher = {mathdoc},
     volume = {10},
     number = {1},
     year = {2007},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MT_2007_10_1_a7/}
}