Refs.:
- Bonazzi, P., Bindi, L., Zoppi, M., Capitani, G.C., and Olmi, F. (2006) Single-crystal diffraction and transmission electron microscopy studies of "silicified" pyrochlore from Narssârssuk, Julianehaab district, Greenland. American Mineralogist: 91: 794-801.
- http://www.koeln.netsurf.de/~w.steffens/nars.htm