* O. H. A. Ali (1993)

 Effect of removal of residual yolk sac on growth, fat absorption and immunity in broiler chicks.

Thesis, University of Khartoum, Sudan

  * O. Ali (2005)

 In vitro Studies of ion Transport in sheep omasum:

 Interaction between Na, Cl and short Chain Fatty Acids.

Thesis, Free university of Berlin, Germany

* Huwaida E. E. Malik, Mohammed E. Salih and Osama H. Ahmed (2010) System of family poultry in rural Sudan. Rural Poultry Development. ISBN 978-3-639-27370-0

VDM Verlag Dr. Mueller GmbH & Co K. G. Saarbrucken, Germany