A longevity study of twins in the Mormon genealogy.
D000206:Actuarial Analysis; D000367:Age Factors; D002835:Christianity; D005260:Female; D005789:Genealogy and Heraldry; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D008136:Longevity; D008297:Male; D011247:Pregnancy; D012189:Retrospective Studies; D012737:Sex Factors; D014427:Twins