Ghumman, S.S., et al. “γ-γ Sum-Coincidence Effects on Relative γ-Ray Intensities in the Decay of 147Nd-147Pm”. Asian Journal of Chemistry, vol. 22, no. 4, Mar. 2010, pp. 3021-4, https://asianpubs.org/index.php/ajchem/article/view/11507.