Quasi-Periodic Pulsations: Fermi GBM results, by Gruber and Lachowicz. This Nugget points out the significance of “red noise” in time-series analyses of the QPP often found in solar flares.

http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/Quasi-Periodic_Pulsations:_Fermi/GBM_Results