Dubrovskis, Vilis, Imants Plūme, Andis Spīdāns, and Indulis Straume. “FACILITY OF BIOGAS PRODUCTION IN LATVIA”. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 1 (June 23, 2007): 46–51. Accessed November 21, 2024. https://journals23.rta.lv/index.php/ETR/article/view/1717.