Martins, Maria de Fátima, and Gesinaldo Ataíde Cândido. “Urban Sustainability Indicators Systems:: The Challenges of the Process of Measurement, Analysis and Monitoring”. Sustainability in Debate, vol. 6, no. 2, Aug. 2015, pp. 138-54, doi:10.18472/SustDeb.v6n2.2015.12686.