@article{05081398, title = {Lightlike ruled surfaces in }, journal = {Balkan Journal of Geometry and its Applications (BJGA)}, volume = {11}, year = {2006}, pages = {88-100}, zbl = {1104.53010}, language = {en}, url = {http://dml.mathdoc.fr/item/05081398} }
Kılıç, Erol; Karadaǧ, H.Bayram. Lightlike ruled surfaces in . Balkan Journal of Geometry and its Applications (BJGA), Tome 11 (2006) pp. 88-100. http://gdmltest.u-ga.fr/item/05081398/