Berryman, E., Wunder, B., Wirth, R., Rhede, D., Schettler, G., Franz, G., Heinrich, W. (2015): An experimental study on K and Na incorporation in dravitic tourmaline and insight into the origin of diamondiferous tourmaline from the Kokchetav Massif, Kazakhstan. - Contributions to Mineralogy and Petrology, 169, 1-16.https://doi.org/10.1007/s00410-015-1116-9