STRUGIELSKA, Ariadna and PIĄTKOWSKA, Katarzyna. Challenges with defning competence for foreign language learning and teaching on the basis of the Common European Framework of Reference***. Theoria et Historia Scientiarum. Online. 13 December 2018. Vol. 15, p. 21. [Accessed 18 August 2024]. DOI 10.12775/ths.2018.002.