Kelvin B. Chang, Bryce W. Edwards, Laszlo Frazer, Erik J. Lenferink, Teodor K. Stanev, Nathaniel P. Stern, Juan C. Nino, and Kenneth R. Poeppelmeier. “Hydrothermal Crystal Growth, Piezoelectricity, and Triboluminescence of KNaNbOF₅.” Journal of Solid State Chemistry 236,  78-82 (2016).
doi:10.1016/j.jssc.2015.07.011