@article{10_4153_CMB_1975_004_4,
     author = {Bovey, J. D. and Erd\"os, Paul and Niven, Ivan},
     title = {Conditions for a {Zero} {Sum} {Modulo} n},
     journal = {Canadian mathematical bulletin},
     pages = {27--29},
     year = {1975},
     volume = {18},
     number = {1},
     doi = {10.4153/CMB-1975-004-4},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1975-004-4/}
}