@article{ERAAMS_2003_09_a6,
     author = {Sun, Zhi-Wei},
     title = {Unification of zero-sum problems, subset sums and covers of {\ensuremath{\mathbb{Z}}}},
     journal = {Electronic research announcements of the American Mathematical Society},
     pages = {51--60},
     publisher = {mathdoc},
     volume = {09},
     year = {2003},
     doi = {10.1090/S1079-6762-03-00111-2},
     url = {http://geodesic.mathdoc.fr/articles/10.1090/S1079-6762-03-00111-2/}
}