[1] KLEFFE J.: Best quadratic unbiased estimators for variance components in mixed linear models. Sankhya 38. 1976, 179-186. MR 0468051 | Zbl 0413.62052

[2] RAO C. R.: Estimation of variance and covariance components-MINQUE theory. Journ. Multivariat. Analysis 1, 1971, 257-275. MR 0301869 | Zbl 0223.62086

[3] RAO C. R., MITRA K. S.: Geneгalized Inverse of Matrices and its Application. J. Wiley, N. York 1971.

[4] RAO. C. R., KLEFFE J.: Estimation of Variance Components. In: Krisnaiah, P. R., ed. Handbook of Statistics, Vol. I. 1-40, North Holland, N. York 1980. Zbl 0476.62058

[5] SEELY J.: Linear spaces and unbiased estimation-application to the mixed linear model. Ann. Math. Statistics, 41, 1970, 1735-1748. MR 0275560 | Zbl 0263.62041