PSR 2303+30: A single system of drifting subpulses, moding and nulling
  Analyses of multiple pulse sequences of B2303+30 reveal that this pulsar has two distinct emission modes. One mode (B) follows a steady even-odd pattern and is more intense. The second mode (Q) is characteristically weak, but has intermittent driftbands with a periodicity of approximately 3 P/cycles, and nulls much more frequently than the B mode. Both modes occur with roughly equal frequency and their profiles have a similar single-humped form with a slight asymmetry. Our observations and analyses strongly suggest that the subpulse driftrates in both modes are linked in a series of cycles, which can be modelled as relaxing oscillations in the underlying circulation rate. 
Stephen L. Redman (1), Geoffrey A.E. Wright (1,2), Joanna M. Rankin   (1) (1. University of Vermont 2. University of Sussex)