TY - JOUR AU - Wiesław Kułaga TI - Degrees of non-definability of the Sacks model JO - Colloquium Mathematicum PY - 1978 SP - 211 EP - 213 VL - 39 IS - 2 PB - mathdoc UR - http://geodesic.mathdoc.fr/articles/10.4064/cm-39-2-211-213/ DO - 10.4064/cm-39-2-211-213 LA - en ID - 10_4064_cm_39_2_211_213 ER -