@article{VMJ_2014_16_1_a6,
     author = {M. S. Chebarikov},
     title = {On the {Ricci} curvature of three-dimensional metric {Lie} algebras},
     journal = {Vladikavkazskij matemati\v{c}eskij \v{z}urnal},
     pages = {57--67},
     year = {2014},
     volume = {16},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMJ_2014_16_1_a6/}
}