A brief description can be found here.

Passive ground cooling

Sanusi, Aliyah N. Z., Li Shao, and Najib Ibrahim. ‘Passive Ground Cooling System for Low Energy Buildings in Malaysia (Hot and Humid Climates)’. Renewable Energy, Selected papers from World Renewable Energy Congress - XI, 49 (1 January 2013): 193–96. https://doi.org/10.1016/j.renene.2012.01.033.