Conference of Geology of Thailand: Towards Sustainable Development and SufficiencyEconomy. Department of Mineral Resources, Bangkok & Nanjing Institute of
-)、Gamma級(並稱世界三線城市,下設三個副級別:Gamma +、Gamma和Gamma -);另外還有Sufficiency(自足型城市,下設兩個副級別: High Sufficiency/高度自足和Sufficiency/自足)這個級別,意即此等城市能夠提供程度足夠的服務,無需明顯地依賴其他全球城市。以下为2020年版Alpha