\input zb-basic \input zb-ioport \iteman{io-port 05472177} \itemau{Dimitrov, S.D.; Kamenski, D.I.} \itemti{Overall stability constants: Estimation by non-linear least squares methods.} \itemso{Comput. Chem. 21, No. 3, 167-173 (1997).} \itemab Summary: The paper presents a comparative study of four non-linear least squares methods for overall stability constants estimation on the basis of complex formation function. Techniques included are the Gauss-Newton method, the Marquardt method, the modified simplex method and the recently proposed method of Dimitrov and Kamenski (1996) [Computers and Chemistry 20, 331--337 (1996)]. Results from 15 experimental data sets are reported to illustrate the applicability of these methods. Additionally, the reliability of different approaches for getting initial parameter guesses, which exploit specific features of the phenomenon studied, are also discussed. \itemrv{~} \itemcc{J.3} \itemut{stability constants; least squares estimation; curve fitting; Newton-type methods} \itemli{doi:10.1016/S0097-8485(96)00025-3} \end