[1] Zierk J et al. Age- and sex-specific dynamics in 22 hematologic and biochemical analytes from birth to adolescence. Clin Chem 2015; 61: 964–73

[2] Harris EK, Boyd JC. On dividing reference data into subgroups to produce separate reference ranges. Clin Chem 1990; 36: 265–70

[3] Clinical and Laboratory Institute Standards document C28-A3c. Defining, establishing, and verifying reference intervals in the clinical laboratory. Approved guideline, 3rd ed. Vol 28 No 30, 2008

[4] Arzideh F et al. An improved indirect approach for determining reference limits from intra-laboratory data bases exemplified by concentrations of electrolytes. J Lab Med 2009; 33: 52–66

[5] Hoffmann G et al. Ein einfaches Verfahren zur Schätzung von Referenzintervallen aus routinemäßig erhobenen Labordaten. J Lab Med 2015; 39: 389–402

[6] Haeckel R et al. Quantity quotient reporting versus z-value for standardizing quantitative laboratory results. J Lab Med 2017; 41: 93–7