Solovei, Mykola. “Legal Regulation of Upgrade Qualification of Pedagogical Workers of Secondary Schools of Ukraine (1990-S – Beginning of the XXI Century)”. Pedagogical Discourse0, no. 20 (May 12, 2016): 172-177. Accessed March 4, 2026. https://www.ojs.kgpa.org.ua/index.php/peddiscourse/article/view/79.