Ghost resonance in a semiconductor laser with optical feedback J. M. Buldú, D. R. Chialvo, C. R. Mirasso, M. C. Torrent and J. García-Ojalvo Europhys. Lett., 64 2 (2003) 178-184 Published online: 01 November 2003 DOI: 10.1209/epl/i2003-00285-3