@misc{Goworek_Tomasz_Positronium, author={Goworek, Tomasz}, howpublished={online}, publisher={Wydaw. UMCS}, language={eng}, type={artykuł}, title={Positronium as a probe of small free volumes in crystals, polymers and porous media}, keywords={positronium, crystals media, polymers media, porous media, positron spectroscopy}, }