Hegazi, N. A., A. Rammah, E. M. Megeed, and A. Hosny,
"Contribution of integrated systems of biological nitrogen fixation to the N-status of intercropped legumes and non-legumes in sandy soils: Berseem clover-rye grass mixtures",
Recent Developments in Biological Nitrogen Fixation Research in Africa., Rabat, Morocco, Hassan II Institute of Agronomy and Veterinary Medicine, pp. 588-596, 1994.
Youssef, H., A. Helmy, M. Fayez, A. Higazy, M. Eid, A. Rammah, I. A. Hanna, M. Monib, and N. A. Hegazi,
"Effect of inoculation with mixed population of associative diazotrophs on yield of pure and mixed stands of legume and non-legume forage crops grown in sandy soils of Egypt",
The Sixth International Symposium on Nitrogen Fixation with Non-Legumes, Ismailia, Egypt, The American University in Cairo Press, pp. 491-492, 1994.
Hamza, M. A., H. Youssef, A. Helmy, G. A. Amin, M. Fayez, A. Higazy, H. M. El-Khawas, M. Monib, M. Z. Sedik, and N. A. Hegazi,
"Mixed cultivation and inoculation of various genera of associative diazotrophs.",
The Sixth International Symposium on Nitrogen Fixation With Non-Legumes. , Cairo, Egypt, The American University in Cairo Press, pp. 319-326, 1994.
Youssef, H., A. Helmy, M. T. Abbas, M. Fayez, A. Higazy, H. El-Khawas, M. Eid, M. Z. Sedik, I. A. Hanna, A. Rammah, et al.,
"Performance of associative diazotrophs introduced to pure and mixed stands of legume and non-legume crops grown in sandy soils of Ismailia and Sinai",
The Sixth International Symposium on Nitrogen Fixation with Non-Legumes, Ismailia, Egypt, The American University in Cairo Press, pp. 423-429, 1994.
Helmy, A., H. Youssef, A. Rammah, I. A. Hanna, M. Eid, E. H. Bedaiwi, and N. A. Hegazi,
"Response of summer forage crops grown in sandy soils to inoculation with mixed population of associative diazotrophs. ",
The Sixth International Symposium on Nitrogen Fixation with Non-Legumes, Cairo, Egypt, The American University in Cairo Press, pp. 489-490, 1994.
Abbas, M. T., A. Rammah, M. Monib, E. H. Ghanem, M. A. M. Eid, M. F. Z. Emara, and N. A. Hegazi,
"Wheat cultivation in sandy soils as affected by N-fertilization and composite inoculation with associative diazotrophs",
The Sixth International Symposium on Nitrogen Fixation with Non-Legumes, Ismaiia-Egypt, The American University in Cairo Press, pp. 485-487, 1994.