1. BP Statistical Review of World Energy—June 2007, Egham, Surrey, UK. BP Distribution Services, p. 45http://www.bp.com/content/dam/bp-country/en_ru/documents/publications_PDF_eng/Statistical_review_2007.pdf
2. Underground Coal Gasification;Couch,2009
3. http://ny.whlib.ac.cn/pdf/Survey_of_Energy_Resources_2007.pdf
4. Operating concept of circulating fluidized bed gasifier from the kinetic point of view
5. Deconstructing deadly details from China’s coal mine safety statistics CLBhttp://www.clb.org.hk/en/content/deconstructing-deadly-details-chinas-coal-mine-safety-statistics