1. Coal: Typology–Physics–Chemistry–Constitution;Van Krevelen,1993
2. Coal: Its Properties, Analysis, Classification, Geology, Extraction, Uses, and Distribution;Moore,1922
3. Major Coalfields of the World;Walker,2000
4. Coal Deposits: Origin, Evolution, and Present Characteristics;Tatsch,1980
5. Coal: The Energy Source of the Past and Future;Schobert,1987