More, J. J., Garbow, B. S., and Hillstrom, K. E. (1981).
Testing unconstrained optimization software.
ACM Transactions on Mathematical Software (TOMS), 7(1), 17-41.
10.1145/355934.355936
BARD, Y. Comparison of gradient methods for the solution of nonlinear parameter estimation
problems SIAM J. Numer. Anal. 7 (1970), 157-186.