[1]
R. Reisfeld, C. K. Jørgensen, A. Bornstein, and H. Berthou, “Photo-electron Spectra of Germanium, Arsenic and Lead-containing Sulphide Glasses Favouring Lanthanide Luminescence”, Chimia, vol. 30, no. 10, p. 451, Oct. 1976, doi: 10.2533/chimia.1976.451.