1. Rojkovic I, Medved J, Walzel E (1989) Rare earth from uranium mineralization occurrences in the permian of the Gemericum, the Western Carpathians. Goologicky Zbornik Geologica Carpathica 40:453–469
2. Mahdy MA, El Hazek NMT, El-Shazly EM (1993) Egypt J Anal Chem 21:81
3. Paschoa AS (1993) Rad Prot Australia 11(4):162
4. Moharram BM (1991) Isotopenpraxis 24(7):199–200
5. Paul AC, Pillai PMB, Horidasan PP, Radhakrishnan S (1998) J Environ Radioact 40(3):109–251