TY - JOUR AU - van Raamt, A F; Mali, W PTM; van Laar, P J; van der Graaf, Y TI - The fetal variant of the circle of Willis and its influence on the cerebral collateral circulation JO - Cerebrovasc Dis IS - 04 VL - 22 PY - 2006 DO - 10.1159/000094007 L3 - PubMed-ID: 16788293 SP - 217 EP - 224 ER -