Haggag, L. F.; Abd El-Migeed, M. M. M.; Fawzi, M. I. F.; Shahin, M. F. M.; Merwad M. A. Influence of spraying Zinc Sulphat and Gibbralic Acid on yield and fruit properties of “Manzanillo” Olives. Int. J. Agric. Tech. 2015, 11, 1599-1611.