Birth order studies: some sources of bias.
D000293:Adolescent; D000328:Adult; D001722:Birth Order; D001723:Birth Rate; D002648:Child; D002675:Child, Preschool; D004641:Emigration and Immigration; D005191:Family Characteristics; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D001523:Mental Disorders; D011159:Population Surveillance; D012494:Sampling Studies; D012801:Sibling Relations; D013223:Statistics as Topic; D006113:United Kingdom