“…However, from the practical point of view, only some eigenvalues and/or eigenvectors of the matrix or submatrices can be known (see [2], [6]). In this sense, in [12], the authors consider a special kind of spectral data, this is, the minimal and maximal eigenvalues of all leading principal submatrices of A n , together with an eigenpair of it. Initially, this special kind of spectral data was introduced by Peng et al in [9], and subsequently, it has been considered by several authors (see [4], [8], [10]- [13]).…”