Ostapenko, Olga, Olga Shevchenko, and Olena Bakum. “ENERGY EFFICIENCY OF HEAT PUMPING STATIONS WITH DIFFERENT HEAT SOURCES ON CONDITION OF VARIABLE OPERATION MODES”. Scientific Works of Vinnytsia National Technical University, no. 4 (November 25, 2015). Accessed April 26, 2024. https://works.vntu.edu.ua/index.php/works/article/view/394.