Distributions of equivalent widths of the [O iii]λ5007 emission line. The distribution of 0.3 <z< 0.7 LGRB sample values (grey) is compared to the SLSN sample (Table A.1; black) in the same redshift range. Furthermore, we plot distributions of SLSN samples from the literature, namely from L15 (blue) and L14 (red). Errors are not taken into account in the case of SLSN measurements as they are negligible.