Putāns, Henriks, Viktorija Zagorska, Imants Ziemelis, and Zanis Jesko. “Research On Solar Energy Collector With Cell Polycarbonate Absorber”. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 1 (August 5, 2015): 213–219. Accessed May 6, 2024. https://journals.ru.lv/index.php/ETR/article/view/914.