The metallicity-luminosity relationship of dwarf irregular galaxies - II. A new approach A. M. Hidalgo-Gámez, F. J. Sánchez-Salcedo and K. Olofsson A&A, 399 1 (2003) 63-76 Published online: 05 February 2003 DOI: 10.1051/0004-6361:20021748