TY  - RPRT
TI  - Using Christmas Bird Count data to assess population dynamics and trends of waterbirds
AU  - G.S. Butcher
AU  - D.K. Niven
AU  - J.R. Sauer
PY  - 2005
UR  - https://pubs.usgs.gov/publication/5224843
ID  - 5224843
ER  -