Chowdhury, M. Z., M. K. Mian, and M. A. Akbar. “Assessment of Self-Incompatibility in Some Improved and Traditional Cultivars of Oleiferous (<i>Brassica rapa</I> L.)”. Bangladesh Journal of Agricultural Research, vol. 32, no. 2, Aug. 2007, pp. 235-46, https://www.banglajol.info/index.php/BJAR/article/view/306.