Citation: Ghose, S.; Sen Gupta, P. K.; Campana, C. F. (1987). Symmetry and crystal structure of monteregianite, Na4K2Y2Si16O38.10H2O, a double-sheet silicate with zeolitic properties Note: Several bond lengths cannot be reproduced with this data, but the authors no longer have the original data, so they cannot check. American Mineralogist, 72, pp. 365-374.