TY  - RPRT
TI  - Evaluation of aerial transects for counting winter mallards
AU  - Kenneth J. Reinecke
AU  - Michael W. Brown
AU  - James R. Nassar
PY  - 1992
DO  - 10.2307/3808867
UR  - https://pubs.usgs.gov/publication/5223021
ID  - 5223021
ER  -