1. Allègre CJ, Caby R (1972) Chronologie absolue du Précambrien de l'Ahaggar occidental. CR Acad Sci Paris 275D:2085?2098
2. Allègre CJ, Caby R, Tatsumoto M (1972) U-Th-Pb systematic of hydroxyapatic intergrowths. Trans AGU 53:4
3. Amli R (1975) Mineralogy and rare earth geochemistry of apatite and xenotime from the Gloserheia granite pegmatite, Froland, Southern Norway. Am Mineral 60:607?620
4. Balashov YA, Pozharitskaya LK (1968) Factors governing the behaviour of rare-earth elements in the carbonatite process. Geokhimiya 3:285?303 (English transl)
5. Bell L, Blenkisop J, Cole TJS, Menagh DP (1982) Evidence from Sr isotope for long-lived heterogenities in the upper mantle. Nature 298:251?253