Citation: Thompson, John G; Withers, Ray L.; Melnitchenko, Alexandra; Palethorpe, Stephen R. (1998). Cristobalite-Related Phases in the NaAlO~2~--NaAlSiO~4~ System. I. Two Tetragonal and Two Orthorhombic Structures. Acta Crystallographica Section B, 54, pp. 531-546.