1. Distribution of the lanthanides in minerals;Adams,1968
2. Bare earths in phosphorites—Geochemistry and potential recovery;Altschuler;U.S. Geol. Surv. Prof. Paper,1967
3. Rare-earth abundances in manganese nodules;Ehrlich,1968
4. Some aspects of the geochemistry of yttrrium and the lanthanides;Fleischer;Geochim. Cosmochim. Acta,1966
5. Rare earth distribution in the marine environment;Goldberg;J. Geophys. Res.,1963