U-Spatial (University of Minnesota)Global coal production by country, 1990 to 2013.https://umn.maps.arcgis.com/home/item.html?id=ab6b5d9c11134189a592af7dcec68442&sublayer=0engPublicGlobal Energy Production and Reserves (Coal Production) [Global] {1990-2013}Web servicesWorld1990-2013University of Minnesota