“…Then they unify several elliptical models, such as nonlinear regressions, mixed-effects model with nonlinear fixed effects, errors-in-variables models, etc. Bias correction for the maximum likelihood estimator and adjustments of the likelihood-ratio statistics are also derived for this general model (see [38], [37]). The elliptical distributions can also be used as the basis to consider robustness in multivariate linear regression, as in [14], [21], [29], [36], [42], [50] and many others.…”