Specification for the construction and acceptance of concrete water pit engineering for petrochemical industry 石油化工混凝土水池工程施工及验收规范
2.
The discovered balin stone lies in a shallow earth . most of them are revealed near the ground . there are two major kinds named water pit and mountain pit 已发现的巴林石埋藏较浅,许多为近地表开采。其主要品种也分为冻地石和与山坑石。