@article{articlea4be4025,
title   = {Two-photon spectroscopy in 'GD''AL''O IND.3'},
author = {Nunes, Luiz Antônio de Oliveira and Padua, S J N and Castro Neto, Jarbas Caiado de},
year = {1990},
doi = {10.1103/PhysRevB.41.4736},
journal   = {Physical Review B}
}