@article{10_4064_cm_86_2_203_207,
     author = {Marek Balcerzak and Udayan Darji},
     title = {Some examples of true $F_{\ensuremath{\sigma}\ensuremath{\delta}}$ sets},
     journal = {Colloquium Mathematicum},
     pages = {203--207},
     publisher = {mathdoc},
     volume = {86},
     number = {2},
     year = {2000},
     doi = {10.4064/cm-86-2-203-207},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-86-2-203-207/}
}