1. Adair SE (1990) Factors influencing wintering diving duck use of coastal ponds in south Texas. MSc Thesis, Texas A&M Univ, College Station, TX
2. Bellrose FC (1980) Ducks, geese and swans of North America. Stackpole Books, Harrisburg, PA
3. Benson WW, Brock DW, Gabica J, Loomis M (1976) Swan mortality due to certain heavy metals in the Mission Lake area, Idaho. Bull Environ Contam Toxicol 15:171?174
4. Boesch DF, Rabalais NN (eds) (1989) Produced waters in sensitive coastal habitats: An analysis of impacts, central coastal Gulf of Mexico. US Dept Int Minerals Manage Serv OCS Rep/MMS 89-0031, Washington, DC
5. Brealey CJ, Walker CH, Baldwin BC (1980) A-esterase activities in relation to the differential toxicity of pirimiphos-methyl to birds and mammals. Pest Sci 11:546?554