Gladkova, V. E., M. A. Yakhyaev, V. E. Korolkov, I. A. Smirnova, I. L. Litvinenko, and J. S. Pinkovetskaya. “The Access of Russian Small Enterprises to Public Procurement Markets: Data Analysis”. Amazonia Investiga, vol. 7, no. 15, Aug. 2018, pp. 20-31, https://amazoniainvestiga.info/index.php/amazonia/article/view/374.