Figure. (IMAGE) Wuhan University Caption The spatial pattern of POIs density (i.e. the number of POIs in 500 m grids) collected from Google Maps (left) and OSM (right) in large (a), middle (b), and small (c) size cities. Credit The authors Usage Restrictions Credit must be given to the creator. License CC BY Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.