Przybylski, G., R. Pujszo, M. Pyskir, J. Pyskir, and M. Bannach. “The wellness of blind and visually impaired young men on the basis of chosen spirometric parameters”. European Journal of Clinical and Experimental Medicine, vol. 9, no. 3, Sept. 2011, pp. 315–324, https://journals.ur.edu.pl/ejcem/article/view/12902.