SGEM 2021 conference proceedings

SGEM 2021. International scientific conference on social sciences. SGEM 2021 conference proceedings. Social sciences : section education and educational research. 1. vyd. Sofia : SGEM World Science Society (SWS Society), 2021. Dostupné na internete: <https://www.sgemsocial.org/index.php/elibrary?view=publication&task=show&id=4659> ISBN 978-3-903438-00-2. ISSN 2682-9959.