Overall natural radioactivity of a phosphate fertilizer industry in Korea M.H. Song, B.U. Chang, S.M. Koh, Y.J. Kim, D.J. Kim and G.H. Kim Radioprotection, 46 6 (2011) S113-S118 Published online: 09 January 2012 DOI: 10.1051/radiopro/20116835s