Sergey V. Laptev, A. F. B. “The Techniques of Distribute Sources of Financing Long-Term Investments Between the State and Oil-Producing Companies: The Experience of Russia and Iraq”. International Journal of Advanced Science and Technology, Vol. 28, no. 13, Nov. 2019, pp. 253 -65, http://sersc.org/journals/index.php/IJAST/article/view/1309.