Estimation of variance components in mixed linear models

summary:The MINQUE of the linear function $\int'\vartheta$ of the unknown variance-components parameter $\vartheta$ in mixed linear model under linear restrictions of the type $\bold R\vartheta = c$ is defined and derived. As an illustration of this estimator the example of the one-way classification model with the restrictions $\vartheta_1 = k\vartheta_2$, where $k \geq 0$, is given