Rizhikovs, Janis, Aigars Paze, Ance Plavniece, Kristaps Stankus, and Inguss Virsis. 2017. “A NOVEL METHOD FOR BIRCH OUTER BARK QUALITY CONTROL USING HIGHER HEATING VALUE”. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 3 (June): 282-85. https://doi.org/10.17770/etr2017vol3.2550.