1. Ahearn, M., Yee, J., & Huffman, W. (2002, July). R;D, productivity, and structural change in US agriculture, 1960-1996. In Presentation at the National Bureau of Economic Research Summer Institute Conference on Research in Income and Wealth Cambridge, Massachusetts July, 29-31.
2. The Benefits from Agricultural Research and Development, Innovation, and Productivity Growth
3. Industry benefits from recent genetic progress in sheep and beef populations
4. Anonymous. (2022). Report on developments in the real sector of 's economy in (2019). Ardabil Province Research and Education Center. (Light livestock research projects report.
5. Asadi, H. and Saidi, A. (2013). Estimating investment returns in research of modified varieties of blue wheat in , Journal of Research and Development, 64, 21-32.