ELGABEUR B. Characterization and stability of essential pseudospectra by measure of polynomially inessential operators. Stud. Univ. Babeş-Bolyai Math. [Internet]. 2025 Dec. 9 [cited 2025 Dec. 15];70(4):685–708. Available from: https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/9782