TY  - RPRT
TI  - Aerial survey as a technique for estimating manatee population size and trend - problems and prospects
AU  - L.W. Lefebvre
AU  - B.B. Ackerman
AU  - Kenneth M. Portier
AU  - K. H. Pollock
PY  - 1995
UR  - https://pubs.usgs.gov/publication/2002796
ID  - 2002796
ER  -