%0 Journal Article %A Giovanni Calvaruso %A Eduardo García-Río %T Algebraic Properties of Curvature Operators in Lorentzian Manifolds with Large Isometry Groups %J Symmetry, integrability and geometry: methods and applications %D 2010 %V 6 %U http://geodesic.mathdoc.fr/item/SIGMA_2010_6_a4/ %G en %F SIGMA_2010_6_a4