@article{01118076, title = {When can the sum of }, journal = {The Electronic Journal of Combinatorics [electronic only]}, volume = {4}, year = {1997}, zbl = {0884.05003}, language = {en}, url = {http://dml.mathdoc.fr/item/01118076} }
Petkovšek, Marko; Wilf, Herbert S. When can the sum of . The Electronic Journal of Combinatorics [electronic only], Tome 4 (1997) . http://gdmltest.u-ga.fr/item/01118076/