@article{article2cc057b2,
title   = {1.5 'mü'm emission and infrared-to-visible frequency upconversion in 'Er POT.+3'/Y'b POT.+3'-doped phosphoniobate glasses},
author = {Barbosa, A. J. and Dias Filho, F. A. and Messaddeq, Y. and Ribeiro, S. J. L. and Gonçalves, Rogéria Rocha and Lüthi, S. R. and Gomes, A. S. L.},
year = {2006},
journal   = {Journal of Non-Crystalline Solids}
}