1. Andrewartha, H. G. and Birch, L. C. 1954.The Distribution and Abundance of Animals, Vol. III, 782Chicago: University of Chicago Press.
2. Baker, A. C., Stone, W. E., Plummer, C. C. and McPhail, M. 1944. 155U.S. Dept. Agr. Misc. Publ. No. 531
3. The Role of Weather in Determining the Distribution and Abundance of Animals