TY  - RPRT
TI  - How much habitat management is needed to meet mallard production objectives?
AU  - L.M. Cowardin
AU  - T.L. Shaffer
AU  - K.M. Kraft
PY  - 1995
UR  - https://pubs.usgs.gov/publication/1001188
ID  - 1001188
ER  -