1. Bakumenko LP, Korotkov PA. Integrated assessment of the quality and the environmental sustainability of the regions’ environment (on the example of the Mari El Republic). 2008. [An electronic resource]. URL: http://pe.cemi.rssi.ru/pe_2008_1_73-92.pdf.
2. Albiter LM, Smirnova SB. Economic and ecological efficiency at the macro level. 2012. [An electronic resource]. URL: http://vestnik.samgtu.ru/uploads/series/1/22/242/2012-3--0013.pdf.
3. UN Millennium Development Goals – backgroung [An electronic resource]. URL: http://russia-un.ru/en/node/30.
4. Rubanov IN, Tikunov VS. Methods of assessing the ecological condition of the environment of the regions of Russia, Problems of Regional Ecology; 2007; 3: 20-28.
5. Bobylev SN, Minakov VS, Solovyov SV, Tretyakov VV. Ecological and economic index of regions of the Russian Federation. 2012. [An electronic resource]. URL: http://www.wwf.ru/resources/publ/book/707.