Morsal, Nizar E. A., 		Mohamed, Ibrahim E., 		Eltayeb, Eltohami I., AND 		Gangi, Ali S..
" Effects of mixed cropping with cowpea and nitrogen source on growth and yield of sunflower (Helianthus annuus L.)" <em>Gezira Journal of Agricultural Science</em> [Online], Volume 14 Number 1 (1 January 2016)