Hreb, M. M., N. Hrona, V. Chumak, O. Vyshnyk, and V. Hreb. “Speech Competence of Primary School Students: Cognitive Approach”. Journal of History Culture and Art Research, vol. 9, no. 2, June 2020, pp. 165-74, doi:10.7596/taksad.v9i2.2437.