- Oil shale fluidized bed retorting technology with CFB furance for burning the by-productsSiirde, Andres; Martins, AntsInternational Oil Shale Symposium : Tallinn, Estonia, June 8-11, 2009 : future energy solutions : come and share your vision!2009 / p. 56-57 http://www.ester.ee/record=b4775098*est