Gabka, K. (1971). The contribution of Friedrich Engels to the development of the scientific theory of language and current problems of Marxist-Leninist linguistics: organized by the Sections of Linguistics and Literary Studies and Marxism-Leninism of the Ernst-Moritz-Arndt-University Greifswald, Sellin on Ruegen, November 26-28, 1970. EAZ – Ethnographisch-Archaeologische Zeitschrift, 12(3), 443–448. https://doi.org/10.54799/OWPK4956