GEAR team members Luis A. López, María Ángeles Cadarso and Jorge E. Zafrilla in collaboration with Tiago Domingos (from University of Lisbon) have published in Proceedings of the National Academy of Sciences of the United States of America (PNAS) the letter entitle «The smarter, the cleaner? Collaborative
footprint: A further look at taxi sharing«. (DOI: 10.1073/pnas.1420242112).