Paris P Tekkis, Peter McCulloch, Adrian C Steger, Irving S Benjamin, Jan D Poloniecki
Tekkis P P, McCulloch P, Steger A C, Benjamin I S, Poloniecki J D.
Mortality control charts for comparing performance of surgical units: validation study using hospital mortality data
BMJ 2003; 326 :786
doi:10.1136/bmj.326.7393.786