AHMAD, M. On semi-invariant $\xi^{\perp}$-submanifolds of Lorentzian para-Sasakian manifolds. International Journal of Maps in Mathematics, [S. l.], v. 2, n. 1, p. 89–98, 2019. Disponível em: https://simadp.com/journalmim/article/view/31. Acesso em: 23 nov. 2024.