1. Oil shales and their analysis;Williams;Fuel,1983
2. Supercritical gas extraction of South African coals;Kershaw;Separation Science and Technology,1982
3. Wang RA, Jia SC, Qin KZ. Study on chemical structure of kerogen of Maoming and Fushen oil shales with supercritical fluid extraction. J. East China Petroleum Institute 1982;6(4):85–92 (in Chinese).
4. Recovery of organic material by supercritical toluene from Turkish Goynuk oil shale;Yurum;Fuel Science and Technology Int.,1990
5. Conversion of Chinese oil shales to liquid products using supercritical extraction;Guo;Erdoel und Kohle, Erdgas-PetroChemie,1986