@article{10_4064_cm_67_2_217_221,
     author = {Piotr Haj{\l}asz},
     title = {A {Sard} type theorem for {Borel} mappings},
     journal = {Colloquium Mathematicum},
     pages = {217--221},
     publisher = {mathdoc},
     volume = {67},
     number = {2},
     year = {1994},
     doi = {10.4064/cm-67-2-217-221},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-67-2-217-221/}
}