  The measure of the distances and luminosities of gamma-ray bursts (GRBs) led
to the discovery that many GRB properties are strongly correlated with their
intrinsic luminosity, leading to the construction of reliable luminosity
indicators. These GRB luminosity indicators have quickly found applications,
like the construction of 'pseudo-redshifts', or the measure of luminosity
distances, which can be computed independently of the measure of the redshift.
In this contribution I discuss various issues connected with the construction
of luminosity-redshift indicators for gamma-ray bursts.
