Zboina, Bożena, Ewelina Dziedzic, Krzysztof Cudzik, Iwona Czerwińska Pawluk, and Walery Zukow. 2019. “Intensity of COPD Symptoms in Comparison With Spirometry Parameters”. Journal of Education, Health and Sport 9 (3):409-23. https://apcz.umk.pl/JEHS/article/view/6721.