@article{JIS_2004__7_2_a3,
     author = {Haanp\"a\"a, Harri},
     title = {Minimum sum and difference covers of abelian groups},
     journal = {Journal of integer sequences},
     publisher = {mathdoc},
     volume = {7},
     number = {2},
     year = {2004},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/JIS_2004__7_2_a3/}
}