title: A ten-year study of twins in Toa Payoh Hospital 1973-1982.
mesh_terms: D004200:Diseases in Twins; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000453:epidemiology; D008297:Male; D011247:Pregnancy; D012189:Retrospective Studies; D014427:Twins