Improving the angular color uniformity and the lumen output for multi-chip white LED lamps by green Ce0.67Tb0.33MgAl11O19:Ce,Tb phosphor Authors Quoc Anh N.D., Lee H.-Y. Publisher Journal of the Chinese Institute of Engineers, Transactions of the Chinese Institute of Engineers,Series A/Chung-kuo Kung Ch'eng Hsuch K'an Publication year 2016