LETTER TO THE EDITOR: Resonant excitation of a layer of Si donors in GaAs Schwarz, N. ; Muller, F. ; Tempel, G. ; Koch, F. ; Weimann, G. Abstract Publication: Semiconductor Science Technology Pub Date: July 1989 DOI: 10.1088/0268-1242/4/7/013 Bibcode: 1989SeScT...4..571S