TY  - RPRT
TI  - Aerial surveys of waterbirds in Alaska 1957-94 : population trends and observer variability
AU  - J.I. Hodges
AU  - J.G. King
AU  - B. Conant
AU  - H.A. Hanson
PY  - 1996
UR  - https://pubs.usgs.gov/publication/itr4
ID  - itr4
ER  -