1. J.R. Bunch and B.N. Parlett. Direct methods for solving symmetric indefinite systems of linear equations. SIAM Journal on Numerical Analysis, 8:639–655., 1971.
2. A. R. Conn and N. Gould. On the location of directions of infinite descent for nonlinear programming algorithms. SIAM Journal on Numerical Analysis, 21 (61): 302–325, 1984.
3. A. R. Conn, N. I. M. Gould, and Ph. L. Toint. Global convergence of a class of trust region algorithms for optimization with simple bounds. SIAM Journal on Numerical Analysis, 25:433–460, 1988. See also same journal 26: 64–767, 1989.
4. A. R. Conn, N. I. M. Gould, and Ph. L. Toint. Testing a class of methods for solving minimization problems with simple bounds on the variables. Mathematics of Computation, 50: 399–430, 1988.
5. A. R. Conn, N. I. M. Gould, and Ph. L. Toint. LANCELOT: a Fortran package for large-scale nonlinear optimization (Release A). Springer Verlag, Heidelberg, Berlin, New York,1992.