1. Underground longterm storage of solar energy — an overview;Civoni;Solar Energy,1977
2. Stockage de l'Energie Solaire dans le Sol pour le Chauffage des serres;Portales,1981
3. Analysis and Performance of an Earth—Air Heat Exchanger;Scott;ASAE Paper No. 65–840,1965
4. Underground storage of heat in solar heating systems;Shelton;Solar Energy,1975
5. Can circulating air through a buried pipe be used to heat and cool greenhouses;Walter;J. Am. Soc. Hort. Sci.,1977