Weis D., Kieffer B., Maerschalk C., Pretorius W. and Barling J. 2005. High-precision Pr-Sr-Nd-Hf isotopic characterization of USGS BHVO-1 and BHVO-2 reference materials. Geochemistry, Geophysics, Geosystems, 6, Q02002, doi:10.1029/2004GC000852.

Weis D., Kieffer B., Maerschalk C., Pretorius W. and Barling J. 2005. High-precision Pr-Sr-Nd-Hf isotopic characterization of USGS BHVO-1 and BHVO-2 reference materials. Geochemistry, Geophysics, Geosystems, 6, Q02002, doi:10.1029/2004GC000852.