  Recent work has produced a wealth of data concerning the chemical evolution
of the galactic bulge, both for stars and nebulae. Present theoretical models
generally adopt a limited range of such constraints, frequently using a single
chemical element (usually iron), which is not enough to describe it
unambiguously. In this work, we take into account constraints involving as many
chemical elements as possible, basically obtained from bulge nebulae and stars.
Our main goal is to show that different scenarios can describe, at least
partially, the abundance distribution and several distance-independent
correlationss for these objects. Three classes of models were developed. The
first is a one-zone, single-infall model, the second is a one-zone,
double-infall model and the third is a multizone, double infall model. We show
that a one-zone model with a single infall episode is able to reproduce some of
the observational data, but the best results are achieved using a multizone,
double infall model.
