SosulskaA., SamborB., and JekiełekM. “Selected Risk Factors in Voice Disorders and Knowledge of Vocal Hygiene in Primary School Teachers. Preliminary Report”. Logopedia Silesiana, Vol. 10, no. 1, June 2021, pp. 1-28, doi:10.31261/LOGOPEDIASILESIANA.2021.10.01.04.