Calcium extraction from Estonian industrial wastes based on ammonium solventsTamm, Kadriann; Viires, Regiina; Kuusik, Rein, keemik; Uibu, MaiEnergy and sustainability VII2018 / p. 465-476 : ill https://doi.org/10.2495/ESUS170431 Conference proceedings at Scopus Article at Scopus Article at WOS