1. IFCC Standardization of HbA1c. Available from: http://www.ngsp.org/prog/IFCCstd.pdf [last accessed on 2008 Dec 22]
2. Factors that interfere with GHB (HbA1c) test results. Available from: http://www.ngsp.org/prog/factors.htm [last accessed on 2008 Dec 22]