TY  - BOOK
AU  - Berthold, P.
TI  - Orientation in birds /ed. by P. Berthold
T2  - Experientia Supplementum, V.60
SN  - 0817626182
U1  - 598.2525 
PY  - 1991///
CY  - Basel
PB  - Birkhauser
ER  -