TY  - RPRT
TI  - Natural cavities used by wood ducks in north-central Minnesota
AU  - D.S. Gilmer
AU  - I.J. Ball
AU  - L.M. Cowardin
AU  - John E. Mathisen
AU  - John H. Riechmann
PY  - 1978
DO  - 10.2307/3800266
UR  - https://pubs.usgs.gov/publication/1001662
ID  - 1001662
ER  -