@article{02121206, title = {Semi-Riemannian manifolds whose Weyl tensor is a Kulkarni-Nomizu square.}, journal = {Publications de l'Institut Math\'ematique. Nouvelle S\'erie}, volume = {71(85)}, year = {2002}, pages = {95-106}, doi = {10.2298/PIM0272095G}, zbl = {1060.53025}, language = {en}, url = {http://dml.mathdoc.fr/item/02121206} }
Głogowska, Małgorzata. Semi-Riemannian manifolds whose Weyl tensor is a Kulkarni-Nomizu square.. Publications de l'Institut Mathématique. Nouvelle Série, Tome 71(85) (2002) pp. 95-106. doi : 10.2298/PIM0272095G. http://gdmltest.u-ga.fr/item/02121206/