1. Standard Methods for the Examination of Water and Wastewater;American Public Health Association,1971
2. Accumulation of dry matter, nitrogen and phosphorus by cultivated water hyacinths;Boyd;Econ. Bot.,1976
3. Nutrient removal by water hyacinths;Cornwell;J. Water Poll. Control Fed.,1977
4. Effect of harvest rate, waste loading, and stocking density on the yield of duckweeds;Culley,1979
5. Cost analysis of aquatic biomass systems;Dynatech R/D Co.,1978