Literature
  • Varley G.C. 1947
  • Natural control of population balance in the knapweed gall-fly.
    J. annual ecology 16: 139-187.
  • Villers C. de 1789
  • Caroli Linnaei entomologia, faunae Suecicae descriptionibus, vol. 3.- Lugduni, Piestre et Delamolliere.