@article{GDZPPN002462028, title = {A Minimal Characterization of the Covariance Matrix.}, journal = {Metrika}, volume = {35}, year = {1988}, pages = {49-52}, zbl = {0638.62046}, url = {http://dml.mathdoc.fr/item/GDZPPN002462028} }
Grübel, R. A Minimal Characterization of the Covariance Matrix.. Metrika, Tome 35 (1988) pp. 49-52. http://gdmltest.u-ga.fr/item/GDZPPN002462028/