PASHAIE, F. On $L_1$-biharmonic timelike hypersurfaces in pseudo-Euclidean space $E_1^4$. Tamkang Journal of Mathematics, [S. l.], v. 51, n. 4, p. 313-332, 2020. DOI: 10.5556/j.tkjm.51.2020.3188. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/3188. Acesso em: 24 nov. 2020.