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, vol. 94, no. 1, July 2023, pp. 67-80, https://www.asrjetsjournal.org/American_Scientific_Journal/article/view/9186.