Zielińska-Sitkiewicz, M. 2020. The Flu : an Analysis of Economic Costs and Morbidity Rates in Poland in the Period 2013-2019 Using Adaptive Prediction Methods. Acta Scientiarum Polonorum. Oeconomia. 19, 4 (Dec. 2020), 139–146. DOI:https://doi.org/10.22630/ASPE.2020.19.4.50.