Yasar, Erol, A. Ceylan Cöken, and Ahmet Yücesan. 2008. “Lightlike Hypersurfaces in Semi-Riemannian Manifold With Semi-Symmetric Non-Metric Connection”. MATHEMATICA SCANDINAVICA 102 (2):253-64. https://doi.org/10.7146/math.scand.a-15061.