1. Luppens JA, Rohrbacher TJ, Osmonson LM, Carter MD. Coal resource availability, recoverability, and economic evaluations in the United States—a summary. In: Pierce BS, Dennen KO, editors. The National Coal Resource Assessment Overview: U.S. Geological Survey Professional Paper 1625–F, Chapter D; 2009. 17 p.
2. Burton E, Friedmann J, Upadhye R. Best practices in underground coal gasification. Lawrence Livermore National Laboratory: Livermore, CA, USA; 2006.
3. BHP Billiton. Case Study B20: Electricity production using underground coal gasification (UCG). Newcastle, Australia; 2002.
4. Friedmann SJ. North America prospects for UCG in a carbon constrained, energy secure world. Presented at the Twenty-Fifth Annual International Pittsburgh Coal Conference, Pittsburgh, PA, Sep 29–Oct 2, 2008, Paper 26–1.
5. Impurity impacts on the purification process in oxy-fuel combustion based CO2 capture and storage system;Li;Appl Energy,2009