@article{JIS_2011__14_9_a5,
     author = {Merca, Mircea},
     title = {Inequalities and identities involving sums of integer functions},
     journal = {Journal of integer sequences},
     publisher = {mathdoc},
     volume = {14},
     number = {9},
     year = {2011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/JIS_2011__14_9_a5/}
}