Putāns, Henriks, Viktorija Zagorska, Imants Ziemelis, and Zanis Jesko. “Research On Solar Energy Collector With Cell Polycarbonate Absorber”.
ENVIRONMENT. TECHNOLOGY. RESOURCES. Proceedings of the International Scientific and Practical Conference 1 (August 5, 2015): 213–219. Accessed April 6, 2025.
https://journals23.rta.lv/index.php/ETR/article/view/914.