R. Włach, P. Książek, B. . Drop, and J. Tkaczuk-Włach, “The assessment of functionality of the Diagnosis-Related Group (DGR) system by its users”, Pol J Public Health, vol. 123, no. 1, pp. 3–6, Jan. 2013, doi: 10.12923/j.0044-2011/123-1/a.01.