1. El Hilo, A. H., Ayoub, A. T. and Abulgasim, A. (1970). Effect of fertilizer and number of rows per ridge on onion seed yield.Agricultural Research Corporation, Miscellaneous Horticultural Reports, 1967–73, 37–40.
2. El Hilo, A. H. and Mohamedali, G. H. (1971). Effect of plant population and nitrogen level on yield of onion seed at Girba.Agricultural Research Corporation, Miscellaneous Horticultural Reports, 1967–73, 50.
3. El Hilo, A. H., Mohamedali, G. H. and Sharf El Deen, E. A. (1971). Effect of fertilizer and number of rows per ridge on onion seed yield.Agricultural Research Corporation, Miscellaneous Horticultural Reports, 1967–73, 41–2.
4. El Hilo, A. H. and Abu El-Gough, A. A. (1973). Onion seed yield from whole and differentially cut bulbs.Agricultural Research Corporation, Miscellaneous Horticultural Reports, 1967–73, 48.
5. El Hilo, A. H. and Abu El-Gough, A. A. (1974). Effect of whole versus cut bulbs on onion seed yield.Agricultural Research Corporation, Hudeiba Research Station Annual Reports, 96.