1. The historical development of underground coal gasification;Olness,1977
2. A one-dimensional model for in situ coal gasification;Thorsness,1978
3. Cena J, Strack S. Lawrence Livermore National Laboratory in situ coal gasification Program Quarterly Progress Report. Report No. UCRL-50026-79-4. U.S.DOE Livermore, CA: Lawrence Livermore National Laboratory, https://e-reports-ext.llnl.gov/pdf/184938.pdf; October through December 1979.
4. Relative merits of alternate linking techniques for underground coal gasification and their system design implications;Gregg,1980
5. Olness DU, Clements W. Lawrence Livermore National Laboratory Insitu coal gasification Program Quarterly Progress Report. Report No. UCRL-50026-80-4.U.S.DOE. Livermore, CA: Lawrence Livermore National Laboratory, https://e-reports-ext.llnl.gov/pdf/187661.pdf; October through December 1980.