Pretorius W., Weis D., Williams G., Hanano D., Kieffer B. and Scoates J.S. 2006. Complete Trace Elemental Characterization of Granitoid (USGSG-2,GSP-2) Reference Materials by High Resolution Inductively Coupled Plasma-Mass Spectrometry. Geostandards and Geoanalytical Research, 30(1), 39-54.