TY  - RPRT
TI  - A survey for mallard pairs in the Atlantic flyway
AU  - H.W. Heusmann
AU  - John R. Sauer
PY  - 1997
DO  - 10.2307/3802116
UR  - https://pubs.usgs.gov/publication/5223388
ID  - 5223388
ER  -