Niekurzak , Mariusz, and Ewa Kubińska-Jabcoń. “The Use of Biogas As a Biofuel for Powering Biogas, Ecology, Renewable Energy Sources”. AUTOBUSY – Technika, Eksploatacja, Systemy Transportowe, vol. 24, no. 6, June 2019, pp. 218-22, doi:10.24136/atest.2019.154.