Problem 11279. - Vitaly Stakhovsky (Am. Math. Mon., 2007)

Double Sum Inequality: 11250. - Sun Wen Cai; Vitaly Stakhovsky (Am. Math. Mon., 2008)

Sliding Beads: 11279. - Vitaly Stakhovsky (Am. Math. Mon., 2008)

An Inequality Proved Without Computer Assistance: 11251. - Marian Tetiva; Vitaly Stakhovsky (Am. Math. Mon., 2008)

An Inequality with Trig: 11308. - Ovidiu Furdui; Vitaly Stakhovsky (Am. Math. Mon., 2009)