@article{NUMA_1971__18_132109,
     author = {K.M. Brown and J.E. jr. Dennis},
     title = {Derivative {Free} {Analogues} of the {Levenberg-Marquardt} and {Gauss} {Algorithms} for {Nonlinear} {Least} {Squares} {Approximation.}},
     journal = {Numerische Mathematik},
     pages = {289--297},
     publisher = {mathdoc},
     volume = {18},
     year = {1971},
     zbl = {0235.65043},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1971__18_132109/}
}