text: RADIUS = 15
  """
  Priedhorsky, R., Chen, J., Lam, S. T. K., Panciera, K., Terveen, L., &
  Riedl, J. (2007, November). Creating, destroying, and restoring value in
  Wikipedia. In Proceedings of the 2007 international ACM conference on
  Supporting group work (pp. 259-268). ACM.
  """
  