1. NASA SP-262;E. Batschelet,1972
2. Benvenuti, S., Fiaschi, V., Fiore, L., Papi, F.: Homing performances of inexperienced and directionally trained pigeons subjected to olfactory nerve section. J. comp. Physiol.83, 81?92 (1973a)
3. Benvenuti, S., Fiaschi, V., Fiore, L., Papi, F.: Disturbances of homing behaviour in pigeons experimentally induced by olfactory stimuli. Monit. zool. ital. (N.S.)7, 117?128 (1973b)
4. Kramer, G.: Über die Heimfindeleistung unter Sichtbegrenzung aufgewachsener Brieftauben. Verh. Dtsch. Zool. Ges. Frankfurt a.M. 1958, 168?176 (1959a)
5. Kramer, G.: Recent experiments on bird orientation. Ibis101, 399?416 (1959b)