Não informado. (1976). Journal of the Rubber Research Institute of Sri Lanka. Rubber Research Institute of Sri Lanka.
Chicago-referens (17:e uppl.)Não informado. Journal of the Rubber Research Institute of Sri Lanka. Agalawatta, Sri Lanka: Rubber Research Institute of Sri Lanka, 1976.
MLA-referens (8:e uppl.)Não informado. Journal of the Rubber Research Institute of Sri Lanka. Rubber Research Institute of Sri Lanka, 1976.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.