1. https://plus.maths.org/content/florence-nightingale-compassionate-statistician
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2. http://riskcalc.sts.org/stswebriskcalc/#/
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3. https://www.cms.gov/research-statistics-data-and-systems/files-for-order/limiteddatasets/medparldshospitalnational.html
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4. http://www.euroscore.org/calc.html
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5. https://www.hcup-us.ahrq.gov/nisoverview.jsp
.