Instruments of subject-to-subject interaction in blended learning: visual didactic regulatorsRail Asadullin, Valeriy Shteinberg, Nataliya Manko, Lyutsiya Vakhidova and Nadezhda SytinaSHS Web Conf., 98 (2021) 05022DOI: https://doi.org/10.1051/shsconf/20219805022