Association of Natural Rubber Producing Countries & Barlow, C. (1976). The progress and development of rubber smallholders: Proceedings of the first seminar held in Medan, Indonesia, 25-27 February 1975. Association of Natural Rubber Producing Countries.
Lua i Stíl Chicago (17ú heag.)Association of Natural Rubber Producing Countries agus Colin Barlow. The Progress and Development of Rubber Smallholders: Proceedings of the First Seminar Held in Medan, Indonesia, 25-27 February 1975. Kuala Lumpur: Association of Natural Rubber Producing Countries, 1976.
Lua MLA (8ú heag.)Association of Natural Rubber Producing Countries agus Colin Barlow. The Progress and Development of Rubber Smallholders: Proceedings of the First Seminar Held in Medan, Indonesia, 25-27 February 1975. Association of Natural Rubber Producing Countries, 1976.