ATINDOGBE, C. C. $\wL_{r}-$biharmonic null hypersurfaces in generalized Robertson-Walker spacetimes. International Journal of Maps in Mathematics, [S. l.], v. 8, n. 2, p. 717–750, 2025. Disponível em: https://simadp.com/journalmim/article/view/350. Acesso em: 5 oct. 2025.