case"B12":str_ref="<a href='http://arxiv.org/abs/1207.7326v1'>Bolton et al., 2012</a>";break;
case"spZ":str_ref="<a href='http://data.sdss3.org/datamodel/files/BOSS_SPECTRO_REDUX/RUN2D/PLATE4/RUN1D/spZline.html'>SDSS spZline data model (DR12)</a>";break;