1. R.H. Byrd, R.B. Schnabel and G.A. Shultz, “Approximate solution of the trust region problem by minimization over two-dimensional subspaces,”Mathematical Programming 40 (1988) 247–263.
2. F.H. Clarke,Optimization and Nonsmooth Analysis, Canadian Math. Soc. Series of Monographs and Advanced Texts (John Wiley, 1983).
3. J.E. Dennis Jr. and R.B. Schnabel,Numerical Methods for Unconstrained Optimization and Nonlinear Equations (Prentice-Hall, Englewood Cliffs, New Jersey, 1983).
4. I.S. Duff, J. Nocedal and J.K. Reid, “The use of linear programming for the solution of sparse sets of nonlinear equations,”SIAM Journal on Scientific and Statistical Computing 8 (1987) 99–108.
5. M. El Hallabi, “A global convergence theory for arbitrary norm trust region methods for nonlinear equations”, Ph.D. Thesis, Rice University, Houston, TX (1987).