Kaczmarek, Janusz. “On Thought and Proposition”. Acta Universitatis Lodziensis. Folia Philosophica. Ethica-Aesthetica-Practica, no. 9 (January 1, 1993): 43–49. Accessed May 13, 2026. https://www.czasopisma.uni.lodz.pl/philosophica/article/view/17751.