Hillman et al., 1978. American Scientist, 66 (4): 442-451 Document reference Hillman, D. S. ; Culley, D. D. Jr., 1978. The uses of duckweed. American Scientist, 66 (4): 442-451Web http://www.jstor.org/stable/27848752Citation key Hillman et al., 1978Datasheets Duckweed