Rajendra Bhatia, Chandler Davis. A Better Bound on the Variance. The American Mathematical Monthly, 107(4):353-357, 2000. [doi]
@article{BhatiaD00, title = {A Better Bound on the Variance}, author = {Rajendra Bhatia and Chandler Davis}, year = {2000}, url = {http://www.jstor.org/stable/2589180}, researchr = {https://researchr.org/publication/BhatiaD00}, cites = {0}, citedby = {0}, journal = {The American Mathematical Monthly}, volume = {107}, number = {4}, pages = {353-357}, }