Beszédes, S., K. Papp-Sziládi, G. Keszthelyi-Szabó, and C. Hodúr. “Detection of Biodegradation Degree of Sludge Using Dielectric Measurement”. Review on Agriculture and Rural Development, vol. 6, no. 1-2, July 2018, pp. 108-12, doi:10.14232/rard.2017.1-2.108-112.