Serrano, O.Y.A., Oliveira, I. de A., Silva, T.G.F. and Barbosa, R.V.R. 2021. Reflections on the concept of healthy cities from three cities in Northeast Brazil. The Journal of Engineering and Exact Sciences. 7, 1 (Mar. 2021), 12121–01. DOI:https://doi.org/10.18540/jcecvl7iss1pp12121-01-12e.