• Investigating the possibilities for valorising phosphoriteTamm, KadriannYearbook 2018 / Geological Survey of Estonia2019 / p. 30-32 : ill https://www.egt.ee/sites/default/files/content-editors/aastaraamat/egt_aastaraamat_eng_web.pdf https://www.ester.ee/record=b5231713*est