Day, J. M. D., Hilton, D. R., Pearson, D. G., Macpherson, C. G., Kjarsgaard, B. A., & Janney, P. E. (2005). Absence of a high time-integrated ³He/(U+Th) source in the mantle beneath continents. Geology, 33, 733-736. https://doi.org/10.1130/g21625.1