Luminescence of Yb2+, Eu2+ and Cu+ in solids / Salvatore LizzoSpectroscopic analysis of erbium-doped silicon and ytterbium-doped indium phosphide / Ingrid GersdorfSpectroscopic analysis of erbium-doped silicon and ytterbium-doped indium phosphide / Ingrid GersdorfValence mixing in YbCuAl : a case study / [by] Wilfridus Cornelis Maria MattensInvestigations on Ce- and Yb-based intermetallic compounds / [by] Robert Arthur ElenbaasMagnetic properties of ytterbium intermediate-valence compounds / Jacobus Cornelis Petrus Klaasse