1. On the eigenproblem for orthogonal matrices;Ammar;Proceedings of the 25th IEEE Conference on Decision and Control,1986
2. Determination of Pisarenko frequency estimates as eigenvalues of an orthogonal matrix;Ammar,1987
3. G. Ammar and L. Reichel, Fast Approximation of Dominant Harmonics by Solving an Orthogonal Eigenvalue Problem, Report BSC 88/51, Bergen Scientific Center, Bergen, Norway.
4. Computing Pisarenko frequency estimates;Cybenko,1985
5. The shifted QR algorithm for Hermitian matrices;Dekker;Linear Algebra Appl.,1971