title: [Variations of the polygonal circle of Willis in the Spanish population].
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D002941:Circle of Willis / Q000002:abnormalities / Q000033:anatomy & histology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D013030:Spain
vernacular_title: Variaciones del polígono arterial de Willis en la problación espanñola.