Composition and properties of the iron hydroxides-cemented lenses in Estonian sandstone of Middle Devonian AgeŠogenova, Alla; Kleesment, Anne-Liis; Hirt, Ann; Pirrus, Enn-Aavo; Kallaste, Toivo; Šogenov, Kazbulat; Vaher, ReinStudia geophysica et geodaetica2009 / 1, p. 111-131