TAJMOUATI, Abdelaziz; BOUA, Hamid; KARMOUNI, Mohammed. QUASI-FREDHOLM, SAPHAR SPECTRA FOR \(C_{0}\) SEMIGROUPS GENERATORS. Italian Journal of Pure and Applied Mathematics, [S. l.], v. 36, p. 359–366, 2016. Disponível em: https://journals.uniurb.it/index.php/ijpam/article/view/6619. Acesso em: 5 sep. 2026.