DRUTA-ROMANIUC, S.-L. New Results on Einstein and $\eta$-Einstein tangent sphere bundles. Tamkang Journal of Mathematics, [S. l.], v. 58, n. 1, 2026. DOI: 10.5556/j.tkjm.58.2027.5837. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/5837. Acesso em: 1 nov. 2026.