@article{AFM_2015_40_1_a6,
     author = {Xing-Gang He and Chun-Tai Liu},
     title = {On the range of \ensuremath{\sum}n=1\ensuremath{\infty} \ensuremath{\pm}cn},
     journal = {Annales Fennici Mathematici},
     pages = {135--148},
     publisher = {mathdoc},
     volume = {40},
     number = {1},
     year = {2015},
     doi = {10.5186/aasfm.2015.4004},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.5186/aasfm.2015.4004/}
}