Inverse eigenvalue problem of interval nonnegative matrices of order \le ۳

In this paper for a given set of real or complex interval numbers \sigma  satisfying  special conditions,  we find an interval nonnegative matrix  C such that for each point set \delta  of given interval spectrum \sigma, there exists a point matrix A of C such that   \delta is its spectrum. We also study some conditions for the  solution   existence of the problem.