Spectra of the H₂S (2_2,0–2_1,1), OCS (18–17), and OC³⁴S (20–19) lines in the warm inner core of the 20 protostars from our sample not shown in Section 3. The red dotted lines represent the values of a Gaussian fit to each of the detected lines. In some cases, the combination of two Gaussian fits was necessary for the fit. The OCS (18-17) line was observed with a spectral resolution of 62.5 kHz while the H₂S and OC³⁴S lines were observed with a spectral resolution of 2 MHz. Gaussian fits have been plotted for the >3σ detections, except for the OC³⁴S were we also show the <3σ fits when the OC³³S counterpart was detected with >3σ.