@article{10_4064_fm226_1_4,
     author = {Ver\'onica Becher and Pablo Ariel Heiber and Theodore A. Slaman},
     title = {Normal numbers and the {Borel} hierarchy},
     journal = {Fundamenta Mathematicae},
     pages = {63--77},
     publisher = {mathdoc},
     volume = {226},
     number = {1},
     year = {2014},
     doi = {10.4064/fm226-1-4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm226-1-4/}
}