Balintova, Magdalena, Stefan Demcak, Adriana Estokova, Marian Holub, and Petra Pavlikova. 2017. “Study of Thermal Reduction of Barium Sulphate for Barium Sulphide Preparation”. International Conference “Environmental Engineering” 10 (January): 1-6. https://doi.org/10.3846/enviro.2017.004.