@article{MET_1976__23_186169,
     author = {A. Chaudhuri},
     title = {A {Non-Negativity} {Criterion} for a {Certain} {Variance-Estimator.}},
     journal = {Metrika},
     pages = {201--206},
     publisher = {mathdoc},
     volume = {23},
     year = {1976},
     zbl = {0346.62009},
     url = {http://geodesic.mathdoc.fr/item/MET_1976__23_186169/}
}