@article{10_4064_aa130_1_4,
     author = {Peter V. Hegarty},
     title = {Some explicit constructions of sets
 with more sums than differences},
     journal = {Acta Arithmetica},
     pages = {61--77},
     publisher = {mathdoc},
     volume = {130},
     number = {1},
     year = {2007},
     doi = {10.4064/aa130-1-4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa130-1-4/}
}