Numerical variation of the presacral vertebral column in three population groups in North America.
D000293:Adolescent; D000328:Adult; D001741:Black or African American; D000368:Aged; D044466:Asian People; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009656:North America; D012447:Sacrum / Q000033:anatomy & histology; D013131:Spine / Q000033:anatomy & histology*; D044465:White People