John Vourdoubas. “Use of Solar Photovoltaic Systems and Heat Pumps for Achieving Net-Zero Carbon Emission Greenhouses Due to Energy Use: A Case Study in Crete, Greece”. American Scientific Research Journal for Engineering, Technology, and Sciences 94, no. 1 (July 26, 2023): 67–80. Accessed September 14, 2025. https://www.asrjetsjournal.org/American_Scientific_Journal/article/view/9186.