@article{article80586413,
title   = {Er, Yb doped yttrium based nanosized phosphors: particle size, "host lattice" and doping ion concentration effects on upconversion efficiency},
author = {Pires, Ana Maria and Heer, Stephan and Güdel, Hans Ulrich and Serra, Osvaldo Antonio},
year = {2006},
journal   = {Journal of Fluorescence}
}