Zubelzu Mínguez, Sergio, Alfonso López Díaz, Miguel Ángel Gutiérrez García, and Fernando Blanco Silva. 2011. “Gravity Methods As a Tool to Calculate Greenhouse Gas Emissions from Road Traffic in Urban Planning”. Revista Ingeniería De Construcción 26 (2):187-207. https://revistahistoria.uc.cl/index.php/ric/article/view/16539.