@ARTICLE{_Contents_2020, volume={vol. 23}, number={No 3}, journal={Polityka Energetyczna - Energy Policy Journal}, howpublished={online}, year={2020}, publisher={Instytut Gospodarki Surowcami Mineralnymi i EnergiÄ… PAN}, type={Contents}, title={Contents}, URL={http://www.czasopisma.pan.pl/Content/118059/PDF-MASTER/spis%20tre%C5%9Bci%20PE%2023-3.pdf}, }