Paper  bibtex   

@article{kenneth_levenberg_method_nodate,
	title = {A {Method} for the {Solution} of {Certain} {Non}-linear {Problems} in {Least} {Squares}},
	url = {https://cs.uwaterloo.ca/~y328yu/classics/levenberg.pdf},
	urldate = {2017-05-29TZ},
	author = {{Kenneth Levenberg}}
}