A. Alkahtani, Y. M., K. Abdussalam Ashour, and J. S. Zsarnóczai. “Factor Analyses for Economic Growth in EU-28 and MENA-4 Countries”. Review on Agriculture and Rural Development, vol. 5, no. 1-2, Jan. 2016, pp. 171-6, doi:10.14232/rard.2016.1-2.171-176.