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2. Ashton PMS 1990. Seedling response of Shorea species across moisture and light regimes in a Sri Lankan rainforest. PhD Thesis Unpublished. Yale University USA.
3. Ashton PMS Zoysa ND de De Zoysa ND 1989. Performance of Shorea trapezifolia (Thwaites) Ashton seedlings growing in different light intensities. Journal of Tropical Forest Science 1(4):356-364; 15 ref.
4. Ashton PS 1980. Dipterocarpaceae. In: Dassanayaka MD Fosberg FR eds. A Revised Handbook to the Flora of Ceylon Volume I. New Delhi India: Amerind Publishing Company Private Limited 401-402.
5. Bandaranaike WM MUS 1991. A list of the endemic plants of Sri Lanka. 1991 39 pp.; 8 ref. Colombo Sri Lanka: Forestry Information Service Forest Department.