MOHAJAN, H. K. Global Hyperbolicity in Space-time Manifold. International Journal For Research In Business, Management And Accounting , [S. l.], v. 2, n. 1, p. 28–42, 2016. Disponível em: https://ijrgo.com/index.php/bma/article/view/459. Acesso em: 1 aug. 2026.