@article{JIS_2011__14_1_a0,
     author = {Rustogi, Kabir and Strusevich, Vitaly A.},
     title = {Convex and {V-shaped} sequences of sums of functions that depend on ceiling functions},
     journal = {Journal of integer sequences},
     publisher = {mathdoc},
     volume = {14},
     number = {1},
     year = {2011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/JIS_2011__14_1_a0/}
}