Rogoža, Artur, Giedrius Šiupšinskas, and Juozas Bielskus. “Case Analysis of Heat Pump Integration in District Heating System”. Mokslas – Lietuvos ateitis / Science – Future of Lithuania 13 (October 11, 2021). Accessed November 29, 2021. https://journals.vgtu.lt/index.php/MLA/article/view/15272.