On multicast beamforming for minimum outagehttp://www.library.tuc.gr/artemis/DT2009-0064/DT2009-0064.pdfhttp://purl.tuc.gr/dl/dias/C8A569E4-FE6F-4D63-BB45-765BD1D485B1On multicast beamforming for minimum outagefree2014-03-24application/pdf