%0 Journal Article %A Aymen Ammar %A Aref Jeribi %A Bilel Saadaoui %T Characterization of the essential approximation s-spectrum and the essential defect s-spectrum in a right quaternionic Hilbert space %J Filomat %D 2023 %P 3513 %V 37 %N 11 %U http://geodesic.mathdoc.fr/articles/10.2298/FIL2311513A/ %R 10.2298/FIL2311513A %G en %F 10_2298_FIL2311513A