Description of a method in Minpack

The Github page for modern Minpack () provides the following citation for the non-linear solver (hybrd) in the package:

  • M. J. D. Powell, A Hybrid Method for Nonlinear Equations. Numerical Methods for Nonlinear Algebraic Equations, P. Rabinowitz, editor. Gordon and Breach, 1970.

But I can’t find the article anywhere (my universities library, google, etc.). Does anyone know of where I can find a good description of Powell’s hybrid method for nonlinear equations?

I found a copy on The Internet Archive, available to be borrowed.

A Hybrid Method for Nonlinear Equations by M. J. D. Powell

I have a rather hefty PDF of the article (pages 87-114); email me if you would like a copy of it.

Also this Mathematica implementation.

And this Handwiki article on Powell’s dog leg method.

Thanks so much! I send a private message asking for the PDF. Really appreciate the info.