1. Kundt three-dimensional left invariant spacetimes;M Boucetta;J. Math. Phys,2022
2. The moduli space of Lorentzian left invariant metrics on three dimensional unimodular simply connected Lie groups;M Boucetta;J. Korean Math. Soc,2022
3. Left invariant metrics and curvatures on connected, simply connected three-dimensional Lie groups;K Y Ha;Math. Nachr,2009
4. Curvatures of left-invariant metrics on Lie groups;J Milnor;Adv. Math,1976