1. A rapidly convergent descent method for minimization;Fletcher, R.;Comput. J.,1963
2. B. A. Murtagh & R. W. H. Sargent, A Constrained Minimization Method With Quadratic Convergence, presented at the I. M. A. Conference on Optimization, held at the University of Keele, 1968.
3. R. Fletcher, A New Approach to Variable Metric Algorithms, U.K.A.E.A. Report HL 69/4734.
4. A survey of numerical methods for unconstrained optimization;Powell, M. J. D.;SIAM Rev.,1970
5. An automatic method for finding the greatest or least value of a function;Rosenbrock, H. H.;Comput. J.,1960