@article{article37388745,
title   = {New abundances of planetary nebulae in the galactic bulge},
author = {Escudero, André Vieira and Costa, Roberto Dell'Aglio Dias da and Maciel, Walter Junqueira},
year = {2004},
doi = {10.1051/0004-6361:20031625},
journal   = {Astronomy and Astrophysics}
}