Left panel: GRB formation rate ψ(z) obtained with the C⁻ method using the BAT6ext sample (black solid line). The dashed red line and the dot-dashed cyan line are the SFR models of Hopkins & Beacom (2006) and Cole et al. (2001) shown here for reference. All the curves are normalised to their maxima. Right panel: luminosity function φ(L₀) obtained with the C⁻ method using the BAT6ext sample (black solid line). The best fit model describing this function is a broken power-law (dashed green line) with (a = −1.32 ± 0.21, b = −1.84 ± 0.24, L_b = 10^{51.45 ± 0.15} erg/s). The orange dot-dashed line is the luminosity function obtained by S12 in the case of pure luminosity evolution.