Cătinaş, E., & Păvăloiu, I. (1997). On approximating the eigenvalues and eigenvectors of linear continuous operators.
Rev. Anal. Numér. Théor. Approx.
,
26
(1), 19-27.
https://ictp.acad.ro/jnaat/journal/article/view/1997-vol26-nos1-2-art3