• Chemical composition of the mineral matter of the Attarat Um GhudranAosaar, Hardi; Puura, Väino; Soesoo, Alvar; Voolma, Margus; Hade, SigridInternational Symposium "Oil shale 100 years" : Estonia, Sept. 20-23, 2016 : [abstracts]2016 / p. 26