Enhancement of the up-conversion luminescence from 'NaYF IND. 4':'Yb POT. 3+','Tb POT. 3+' - Hölsa, Jorma; Laihinen, Tero; Laamanen, Taneli; Lastusaari, Mika; Pihlgren, Laura; Rodrigues, Lucas Carvalho Veloso; Soukka, Tero (Physica B, 2014)