REYNALDA, B. .; SYLVIANI, S.; TRISKA, A. . Foundations of Krein Spaces and the Nonequivalence of Pythagorean Orthogonality. Indonesian Journal of Applied Mathematics and Statistics, [S. l.], v. 3, n. 1, p. 27–32, 2026. DOI: 10.71385/idjams.v3i1.35. Disponível em: https://idjams.com/index.php/jms/article/view/35. Acesso em: 3 nov. 2026.