Khatikarn, B. and Lavapaurya, T. (1966) “Studies on Vegetable Seed Production, 1963 – 1965 1”, Agriculture and Natural Resources. Bangkok, Thailand, 6(1), pp. 7–15. available at: https://li01.tci-thaijo.org/index.php/anres/article/view/240629 (accessed: 19 September 2026).