Thongsamut, W., Udomprasert, N. and Pornprom, T. 2010. Effects of Plant Spacing on Light Interception, Growth and Yield of Sunflower (Helianthus annuus L.) . Thai Agricultural Research Journal. 28, 2 (Aug. 2010), 187. DOI:https://doi.org/10.14456/thaidoa-agres.2010.7.