
Introduction.- Paleosedimentary Environments And Karst Characteristics Of Ordovician Limestone In North China Coalfields.- Water-Bearing And Water-Resisting Properties Of Top Of Ordovician Limestone In North China Coalfields.- Utilizability Of Weathered And Filled Zone Of...

Introduction.- Paleosedimentary Environments And Karst Characteristics Of Ordovician Limestone In North China Coalfields.- Water-Bearing And Water-Resisting Properties Of Top Of Ordovician Limestone In North China Coalfields.- Utilizability Of Weathered And Filled Zone Of...