SZCZECHOWICZ, Bartosz, KRYCZKA, Małgorzata and ALEJZIAK, Wiesław. Performance of Empirical Research as a Method for Achieving Professional Students’ Competence: a Case Study of Teaching Sales Skills to Future Employees of the Beauty Industry. Journal of Education, Health and Sport. Online. 15 February 2023. Vol. 13, no. 4, pp. 21-36. [Accessed 28 June 2025]. DOI 10.12775/JEHS.2023.13.04.002.