References

  • Coombs, F. 1978. The crows, A study of the Corvids of Europe. Batsford, London.
  • Goodwin, D. 1986. Crows of the World. The British Museum of Natural History, London.
  • Keve, A. 1969. Der Eichhäher, Garrulus glandarius. Die Neue Brehm-Bücherei, Wittenber Lutherstadt.
  • Madge, S. & Burn, H. 1994. Crows and Jays, Christopher Helm, London.