1. J. W. Goodman, “Introduction to Fourier Optics”, McGraw Hill, New York (1968).
2. D. G. Luenberger, “Optimization by Vector Space Methods”, Wiley, New York (1969), p. 161.
3. G. Strang, “Linear Algebra and its Applications”, Harcourt Brace Jovanovich, Orlando (1980), p. 224.
4. R. K. Hansen, “ROVI - Akustisk sensor for undervanns robot”, Dr.Scient Thesis, University of Bergen, Bergen (1990).
5. J. H. Wilkinson, “The Algebraic Eigenvalue Problem”, Oxford University Press, Oxford (1988), p. 189.