Inequalities Involving Altitudes and Exradii: 10759. - Calin Popescu; Achilleas Sinefakopoulos (Am. Math. Mon., 2000)

Problem 10852. - Calin Popescu (Am. Math. Mon., 2001)

Problem 10864. - Calin Popescu (Am. Math. Mon., 2001)

Comparing a Sum over Quadratic Residues and Nonresidues: 10743. - Calin Popescu; O. P. Lossers (Am. Math. Mon., 2001)

A Divisibility Result for a Combination of mth Powers: 10770. - Calin Popescu; Jim Vandergriff; Jim Delany (Am. Math. Mon., 2001)

Problem 10943. - Calin Popescu (Am. Math. Mon., 2002)

A Sum Related to Quadratic Residues: 10852. - Calin Popescu; Roy Barbara; Omran Kouba (Am. Math. Mon., 2002)

Compact Subsets Countable: 10864. - Calin Popescu; Xiaoshen Wang; Thomas McMillan (Am. Math. Mon., 2002)

Problem 11012. - Calin Popescu (Am. Math. Mon., 2003)

Problem 11100. - Calin Popescu (Am. Math. Mon., 2004)

A Divisibility Result: 10943. - Calin Popescu; et al. (Am. Math. Mon., 2004)

Cube Sum Inequalities: 11012. - Calin Popescu; Chu Wenchang (Am. Math. Mon., 2005)

A Subset-Sum Inequality: 11100. - Calin Popescu; Richard Stong (Am. Math. Mon., 2006)