Liu, Weijun, et al. “Blue Shift in the Oriented Cuprous Oxide Micro Structures Prepared via PEG-400 As the Soft Template by Γ-Irradiation”. Asian Journal of Chemistry, vol. 23, no. 11, Sept. 2011, pp. 4795-8, https://asianpubs.org/index.php/ajchem/article/view/10985.