References and Further Reading for Multidimensional Root Finding - GNU Scientific Library -- Reference Manual

The original version of the Hybrid method is described in the following articles by Powell,

M.J.D. Powell, “A Hybrid Method for Nonlinear Equations” (Chap 6, p 87–114) and “A Fortran Subroutine for Solving systems of Nonlinear Algebraic Equations” (Chap 7, p 115–161), in Numerical Methods for Nonlinear Algebraic Equations, P. Rabinowitz, editor. Gordon and Breach, 1970.

The following papers are also relevant to the algorithms described in this section,

J.J. Moré, M.Y. Cosnard, “Numerical Solution of Nonlinear Equations”, ACM Transactions on Mathematical Software, Vol 5, No 1, (1979), p 64–85
C.G. Broyden, “A Class of Methods for Solving Nonlinear Simultaneous Equations”, Mathematics of Computation, Vol 19 (1965), p 577–593
J.J. Moré, B.S. Garbow, K.E. Hillstrom, “Testing Unconstrained Optimization Software”, ACM Transactions on Mathematical Software, Vol 7, No 1 (1981), p 17–41