Jahangir, A., R. Mondal, K. Nada, S. Afoze, and M. Hakim. “Response of Nitrogen and Phosphorus Fertilizer and Plant Spacing on Growth and Yield Contributing Character of Sunflower”. Bangladesh Journal of Scientific and Industrial Research, vol. 41, no. 1, Aug. 2007, pp. 33-40, doi:10.3329/bjsir.v41i1.258.