The coal. "Sui Shu WANG Shao-Chuan": "this warm wine and roast, with Carboniferous, wood, bamboo fire, grass fire, hemp roots of plant fire, smell different." Ouyang Song, "turn to the life record" Volume II: "Hong cake , Carboniferous also. for burning incense, the fire of a cake can be all day immortal. "Qingxu to rise," Sunburn Yan "Poetry:" Sunburn I owned Carboniferous, of office by Xuanshuang. "Fan Wenlan Cai Meibiao such as" General History of China "Introduction: "Cao Cao began late Eastern Han Dynasty Carboniferous."