Tony, M. A., A. Butschke, J. Zagon, H. Broll, M. Schauzu, S. A. Awadalla, H. M. Hafez, and G. Flachowsky,  "Incidence of genetically modified soyabean and maize as animal feed in Egypt",  Journal of Animal and Feed Sciences, vol. 12, pp. 325-339, 2003.