Mydlikowski, Remigiusz, and Krzysztof Maniak. “Measurement of Electromagnetic Field Component Emissions As a Precursor of Emerging Hazard in Coal Mines”. Journal of Telecommunications and Information Technology, vol. 78, no. 4, Dec. 2019, pp. 30-35, https://doi.org/10.26636/jtit.2019.135419.