Granulation of oil shale ashes and the potentiality of use the product in agricultureHälvin, Herki; Kaljuvee, Tiit; Kuusik, Rein, keemikProceedings of the 27th International Conference on Solid Waste Technology and Management : March 11-14, 2012, Philadelphia, PA U.S.A2012 / p. 1201-1209 : ill