TY  - RPRT
TI  - An aerial sightability model for estimating ferruginous hawk population size
AU  - L.W. Ayers
AU  - S.H. Anderson
PY  - 1999
DO  - 10.2307/3802489
UR  - https://pubs.usgs.gov/publication/70022046
ID  - 70022046
ER  -