Histograms of the QPP periods. Left: the black solid line shows all QPP periods combined and the dotted red line shows a Gaussian fit to the overall distribution, which corresponds to an average QPP period of  s for the set of flares examined. Right: the same histogram but with the QPP periods separated based on which instrument was used. The blue line shows the QPP periods detected in the GOES/XRS wavebands with a 2 s cadence, and the green line shows those detected by EVE/ESP, Fermi/GBM, NoRH, and Vernov/DRGE with a 1 s cadence. The distribution for GOES/XRS appears to be shifted slightly towards longer periods than the other instruments.