@article{10_4064_fm_158_2_181_194,
     author = {Etienne Matheron},
     title = {How to recognize a true $\ensuremath{\Sigma}^0_3$ set},
     journal = {Fundamenta Mathematicae},
     pages = {181--194},
     publisher = {mathdoc},
     volume = {158},
     number = {2},
     year = {1998},
     doi = {10.4064/fm-158-2-181-194},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-158-2-181-194/}
}