1. Batschelet E (1965) Statistical methods for the analysis of problems in animal orientation and certain biological rhythms. Am Inst Biol Sci, Washington DC
2. Batschelet E (1972) Recent statistical methods for orientation data. In: Galler S, Schmidt-Koenig K, Jacobs J, Belleville R (eds) Animal orientation and navigation. NASA Spec Pubi 262. US Gov Print Off, Washington DC, p 61
3. Keeton WT (1973) Release-site bias as a possible guide to the “map” component in pigeon homing. J Comp Physiol 86: 1–16
4. Keeton WT (1974) The orientational and navigational basis of homing in birds. In: Advances in the study of behavior, vol V. Academic Press, London New York, p 47
5. Kramer G (1957) Experiments on bird orientation and their interpretation. Ibis 99: 196–227