6Zhenqi Hu,Impact of Coal Mining Subsidence on Farmland in Eastern China, International Journal of Surface Mining, Reclanmation and Environment 11(1997).
7Zhenqi Hu, Subsidence Land Reclamation by Use of a Hydraulic Dredge Pump in Chinese Coal Mines, Mining Technology, 1996, 78(895) :79-81.
8Zhenqi Hu,The Technique of Reclaiming Subsidence Areas by Use of a Hydraulic Dredge Pump in Chinese Coal Mines,International Journal of Surface Mining, Reclamation and Environment, 1994,8 ( 4 ) : 137 - 140.