Blaabjerg O., Nørgaard I., Blom M., Rahbek Nørgaard J., Hyltoft Petersen P., Gry H., and Uldall A. “Reference Intervals Based on a Danish Population”. Upsala Journal of Medical Sciences, vol. 99, no. 3, July 1994, pp. 315-38, doi:10.3109/03009739409179376.