1. Appleman D.E., Evans H.T., 1973.Indexing and least square refinement of powder diffraction data, Job 9412. U.S. Geological Survey Comp. Contrib., 20, 62 pp.
2. Belkin H. E., De Vivo B., Lima A., Torok K., 1996.Magmatic (silicates/saline/sulfur-rich/CO 2)immiscibility and zirconium and rare-earth element enrichment from alkaline magma chamber margins: evidences from Ponza Island, Pontine Archipelago, Italy. Eur. J. Mineral., 8: 1401–1420.
3. Cozzupoli D., Federico M., Fornaseri M., 1976. Mineralizzazione calcitico-apatitico-fluoritica in giacitura filoniana in un cono di scorie presso Sacrofano (regione Sabazia). Rend. S. I. M. P., 32 (1): 197–214.
4. Dai Y., Hughes J.M., 1989.Crystal-structure refinements of vanadinite and pyromorphite. Can. Mineral., 27: 189–192.
5. Della Ventura G., Di Lisa A., Marcelli M., Mottana A., Paris E., 1992.Composition and structural state of alkali feldspars from ejecta in the Roman potassic province, Italy; petrological implications. Eur. J. Mineral., 4: 411–424.