TY  - RPRT
TI  - Some considerations in modeling the mallard life cycle
AU  - Douglas H. Johnson
AU  - J.D. Nichols
AU  - M.J. Conroy
AU  - L.M. Cowardin
PY  - 1988
UR  - https://pubs.usgs.gov/publication/5210078
ID  - 5210078
ER  -