Vambol, V., Kowalczyk-Juśko, A., Jóźwiakowski, K., Mazur, A., Vambol, S. and Khan, N.A. 2022. Investigation in Techniques for Using Sewage Sludge as an Energy Feedstock: Poland’s Experience. Ecological Questions. 34, 1 (Oct. 2022), 91–98. DOI:https://doi.org/10.12775/EQ.2023.007.