SPIE Proceedings [SPIE SPIE's International Symposium on Optical Science, Engineering, and Instrumentation - Denver, CO (Sunday 18 July 1999)] Nonimaging Optics: Maximum Efficiency Light Transfer V - <title>Maximum gap of ideal concentrators for cylindrical absorbers</title>Ries, Harald; Muschaweck, Julius A.; Winston, Roland · 1999

SPIE Proceedings [SPIE Optical Science, Engineering and Instrumentation '97 - San Diego, CA (Sunday 27 July 1997)] Nonimaging Optics: Maximum Efficiency Light Transfer IV - <title>Asymmetrical cone-type secondary concentrators for Fresnel-type reflectors in solar towers</title>Spirkl, Wolfgang; Timinger, Andreas; Ries, Harald; Kribus, Abraham; Muschaweck, Julius A.; Winston, Roland · 1997