1. ATSDR, 1990a. Toxicological Profile for Radium. CAS# 7440-14-4, NTIS PB/91/180414/AS.
2. ATSDR, 1990b. Toxicological Profile for Thorium. CAS# 7440-29-1, NTIS PB/91/180448/AS.
3. ATSDR, 1999. Toxicological Profile for Uranium. CAS# 7440-61-1, NTIS PB/99/163362.
4. Benes, P., 1990. Radium in (continental) surface water. In: The Environmental Behaviour of Radium. IAEA. Technical Reports Series No. 310, Vienna.
5. About the assumption of linearity in soil-to-plant transfer factors for uranium and thorium isotopes and 226Ra;Blanco Rodríguez;The Science of the Total Environment,2002