SHAPIRO, Roberta. Algebraic Curvature Tensors of Einstein and Weakly Einstein Model Spaces. The PUMP Journal of Undergraduate Research, [S. l.], v. 2, p. 30–43, 2019. DOI: 10.46787/pump.v2i0.170. Disponível em: https://journals.calstate.edu/pump/article/view/170. Acesso em: 3 jul. 2024.