TY  - RPRT
TI  - Dieldrin and eggshell thickness in ducks
AU  - P.N. Lehner
AU  - A. Egbert
PY  - 1969
DO  - 10.1038/2241218a0
UR  - https://pubs.usgs.gov/publication/5221262
ID  - 5221262
ER  -