1. Kungl. Suenska Vetensk. akad. Handl.;Hultqvist;Fjarde serien Band 6,1956
2. An evaluation of radiation and dust hazards at a mineral sand processing plant;Johnston;Hlth Phys.,1991
3. Radioactivity in zirconium oxide powders used in industrial applications;Lischinsky;Hlth Phys.,1991
4. The radiological implications of using by-product hypsum as building material;O'Riorden;Report NRPB-R7,1972
5. Uranium and radium-226 in florida phosphate materials;Sessler;Hlth Phys.,1979