Amer, HA; Shawky, S; Hussein, MI; Abd el-Hady, ML (2002). "Radiological study of exposure levels in El Maghara underground coal mine". Journal of Environmental Monitoring4 (4): 583–587. doi:10.1039/b202693g. PMID12196005.
nih.gov
ncbi.nlm.nih.gov
Amer, HA; Shawky, S; Hussein, MI; Abd el-Hady, ML (2002). "Radiological study of exposure levels in El Maghara underground coal mine". Journal of Environmental Monitoring4 (4): 583–587. doi:10.1039/b202693g. PMID12196005.