Brusov, P.N., T.V. Filatova, N.P. Orekhova, and V.L. Kulik. 2018. “Rating Methodology: New Look and New Horizons”. Journal of Reviews on Global Economics 7 (March):63-87. https://www.lifescienceglobal.com/pms/index.php/jrge/article/view/5277.