@article{EXMA_1996__5_2_231422,
     author = {Calkin, Neil J. and Finch, Steven R.},
     title = {Conditions on periodicity for sum-free sets.},
     journal = {Experimental mathematics},
     pages = {131--137},
     publisher = {mathdoc},
     volume = {5},
     number = {2},
     year = {1996},
     zbl = {0871.11013},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EXMA_1996__5_2_231422/}
}