Radukic, Snezana, and Dusan Perovic. “Improving Eco - Efficiency Through Overcoming Sustainability Challenges: A Case Study For BSEC Member States”. Management:Journal of Sustainable Business and Management Solutions in Emerging Economies, vol. 24, no. 2, Sept. 2019, pp. 1-12, doi:10.7595/management.fon.2018.0016.