@article{10_4064_cm_39_2_211_213,
     author = {Wies{\l}aw Ku{\l}aga},
     title = {Degrees of non-definability of the {Sacks} model},
     journal = {Colloquium Mathematicum},
     pages = {211--213},
     publisher = {mathdoc},
     volume = {39},
     number = {2},
     year = {1978},
     doi = {10.4064/cm-39-2-211-213},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-39-2-211-213/}
}