Fotsing Tetsing, H., C. Atindogbé, and F. Nkageu. “Normalized Null Hypersurfaces in the Lorentz-Minkowski Space Satisfying $L_r X =U X +b$”. Tamkang Journal of Mathematics, vol. 54, no. 4, Aug. 2022, pp. 353-78, doi:10.5556/j.tkjm.54.2023.4851.