• Backfilling and waste management in Estonian oil shale industryPastarus, Jüri-Rivaldo; Tohver, Tarmo; Vali, ErikInternational Oil Shale Symposium : Tallinn, Estonia, June 8-11, 2009 : future energy solutions : come and share your vision!2009 / p. 48-49 http://www.ester.ee/record=b4775098*est