We find the best possible constants and such that the double inequalities + + + + + + + + hold for all with , where , , and are, respectively, the geometric, arithmetic, and quadratic means and , , , and are the Neuman means.
"Sharp Geometric Mean Bounds for Neuman Means." Abstr. Appl. Anal. 2014 1 - 6, 2014. https://doi.org/10.1155/2014/949815