Understanding masturbation.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001208:Asia; D002648:Child; D002675:Child, Preschool; D003075:Coitus; D005060:Europe; D005260:Female; D049672:History, 19th Century; D049673:History, 20th Century; D049690:History, Ancient; D049691:History, Medieval; D006801:Humans; D007223:Infant; D008297:Male; D008418:Masturbation; D008875:Middle Aged; D009948:Orgasm; D013483:Superstitions / Q000266:history; D014481:United States