TY  - RPRT
TI  - Densities of breeding American black ducks in southcentral Maine: 1958-60 and 1978-80
AU  - J. R. Longcore
AU  - J.K. Ringelman
PY  - 1997
UR  - https://pubs.usgs.gov/publication/5210974
ID  - 5210974
ER  -