Analysis of Strong Outbursts in Selected Blazars from the Metsahovi and   UMRAO Monitoring Databases
  Frequency-dependent time lags for strong outbursts in four gamma-blazars are determined. The time lags for two adjacent outbursts in 2230+114 are correlated with the outburst amplitudes. There is evidence that bright outbursts in 2230+114 appear with a quasi-period of (8.0 +- 0.3) yr. 
T. B. Pyatunina, N. A. Kudryavtseva, D. C. Gabuzda, S. G. Jorstad, M.   F. Aller, H. D. Aller, H. Terasranta