@article{10_4064_aa_34_1_9_24,
     author = {Eugene Levine and Joseph O'Sullivan},
     title = {An upper estimate for the reciprocal sum of a sum-free sequence},
     journal = {Acta Arithmetica},
     pages = {9--24},
     publisher = {mathdoc},
     volume = {34},
     number = {1},
     year = {1977},
     doi = {10.4064/aa-34-1-9-24},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa-34-1-9-24/}
}