@conferenceObjectPart{BerniMennigSchmidt_2003,
title={Erbium-doped sol-gel materials for optical applications},
author={Berni, Anette and Mennig, Martin and Schmidt, Helmut K.},
isbn={0-8194-4739-0},
doi={http://dx.doi.org/10.22028/D291-24730},
year={2003}
}