Yasar, Erol, A. Ceylan Cöken, and Ahmet Yücesan. “Lightlike Hypersurfaces in Semi-Riemannian Manifold With Semi-Symmetric Non-Metric Connection”. Mathematica Scandinavica 102, no. 2 (June 1, 2008): 253–264. Accessed July 24, 2026. https://journals.msp.org/mscand/article/view/636.