@article{10_4064_cm105_1_3,
     author = {Vanda F\"ul\"op},
     title = {Double sine series with nonnegative coefficients
  and {Lipschitz} classes},
     journal = {Colloquium Mathematicum},
     pages = {25--34},
     publisher = {mathdoc},
     volume = {105},
     number = {1},
     year = {2006},
     doi = {10.4064/cm105-1-3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm105-1-3/}
}