2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/123177We describe the two projects by which we are assembling a database of near-IR luminosities and direct oxygen abundances for both high- and low-mass star-forming galaxies in the nearby Universe. This will eventually allow us to construct the first reliable and homogeneous luminosity-metallicity relation, to be compared to theoretical models of galactic evolution, and to the relations for galaxies at higher redshifts.To appear in the proceedings of "From Stars to Galaxies: Building the pieces to build up the Universe" (Venice, October 16-20, 2006). ASP Conf. SerAstrophysicstext