2021. Evaluation of experience of distance-learning that was provided by Greek Public Institutes of Vocational Training (PIVT) during the pandemic COVID-19 crisis. Annual of Sofia University St. Kliment Ohridski. Faculty of Mathematics and Informatics. 108, (Dec. 2021), 5–15. DOI:https://doi.org/10.60063/gsu.fmi.108.5-15.