Rydzewski, Piotr, and Tomasz Zabolski. “Theory of Quality”. Acta Universitatis Lodziensis. Folia Philosophica. Ethica-Aesthetica-Practica, no. 5 (January 1, 1988): 47–60. Accessed October 2, 2024. https://czasopisma.uni.lodz.pl/philosophica/article/view/17571.