ZASCERINSKA, Jelena; AĻEKSEJEVA , Ludmila; ZASCERINSKIS, Mihails; GUKOVICA, Olga; ALEKSEJEVA, Anastasija. THE IMPACT OF COVID-19 ON THE IMPROVEMENT OF TEACHING SKILLS ON PROBLEM-BASED LEARNING (PBL). International Journal for 21st Century Education, [S. l.], v. 7, n. 1, p. 42–59, 2021. DOI: 10.21071/ij21ce.v7i1.13074. Disponível em: https://journals.uco.es/ij21ce/article/view/13074. Acesso em: 13 dic. 2025.