Elamin, Elwaleed, AND 		Omer, Mekki.
" Effect of some tillage methods and sowing dates   on bulk density,  soil moisture  and sorghum yield   in the rainfed  areas of  northern Gedarif ,  Gedarif State , Sudan" <em>Gezira Journal of Agricultural Science</em> [Online], Volume 15 Number 1 (1 June 2017)