TY  - RPRT
TI  - Population trends of North American sea ducks based on Christmas Bird Count and Breeding Bird Survey data
AU  - D.K. Niven
AU  - J.R. Sauer
AU  - G.S. Butcher
PY  - 2005
UR  - https://pubs.usgs.gov/publication/5211320
ID  - 5211320
ER  -