I'm looking for a clear exposition of the Davidon-Fletcher-Powell (DFP) and Broyden-Fletcher-Goldfarb-Shanno (BFGS) methods to find a maximizer or minimizer of a function. My current sources of information on these methods are (1) Greene's "Econometric Analysis" (3rd edition), (2) Dahlquist and Bjorck's "Numerical Methods," and (3) Wikipedia. There seems to be some inconsistency between these 3 expositions. Partly it's because the formulas for maximization differ from the formulas for minimization. Minimizing f is equivalent to maximizing minus f, and I should be able to use this principle to derive the formulas for minimization from those for maximization (or vice versa). However, I'm still getting sign inconsistencies when I carry this program through. The local libraries are of limited usefulness for this matter, so I'm hoping someone on this list has a clear exposition of these methods in PDF form (or MS Word, or EXP) and can send it to me as an attachment. Thanks, Frank Benford