Water hyacinth: a plant with prolific bioproductivity and photosynthesis. By S. Matai and D.K. Bagchi. 1980. pp. 144-148 in: Gnanam, A., Krishnaswamy, S., and Kahn, J.S. (editors), Proc. Internat. Symp. on Biol. Applications of Solar Energy. MacMillan Co. of India, Madras. Cited in Handbook of Energy Crops. By J. Duke.
Medicinal plants of east and southeast Asia. By L.M Perry. 1980. MIT Press, Cambridge. Cited in Handbook of Energy Crops. By J. Duke (Available only online. An excellent source of information on numerous plants.)