1. van Krevelen DW et al (1954) Fuel 1954(33):79
2. Zhu PZ, Gao JS (1984) Coal chemistry. Shanghai Science and Technology Press, Shanghai, p 74
3. Yu JS (2000) Coal chemistry. Metallurgical Industry Press, Beijing, p 108
4. He XM (2010) Coal chemistry. Metallurgical Industry Press, Beijing, p 79
5. van Krevelen DW (1981) Coal. Elsevier Scientific Publishing Company, Amsterdam, p 351