1. Development of Union Oil Co. Upflow Retorting Technology;Hopkins,1976
2. New Developments in Oil Shale Retorting by Union Oil Co.;Duir,1977
3. Union's retort B technology;Dhondt,1976
4. Oil shale retorting technology;Duir;Chem. Eng. Progr.,1983
5. Premium syncrude from oil shale using Union oil technology;Miller,1982