TY  - RPRT
TI  - Winter bird population studies and project prairie birds for surveying grassland birds
AU  - D.J. Twedt
AU  - P.B. Hamel
AU  - M.S. Woodrey
PY  - 2008
UR  - https://pubs.usgs.gov/publication/5224857
ID  - 5224857
ER  -