TY  - RPRT
TI  - Aerial surveys of waterfowl production in North America, 1955-71
AU  - Charles J. Henny
AU  - David R. Anderson
AU  - Richard S. Pospahala
PY  - 1972
UR  - https://pubs.usgs.gov/publication/ssrw160
ID  - ssrw160
ER  -