Mazurenko, A., Denysova, A., Balasanian, G., Klimchuk, A. and Borysenko, K. 2017. Improving the operation modes efficiency in heat pump systems of hot water supply with the two-stage heat accumulation. Eastern-European Journal of Enterprise Technologies. 1, 8 (85) (Feb. 2017), 27–33. DOI:https://doi.org/10.15587/1729-4061.2017.92495.