Methods of test for masonry units - Part 9: Determination of volume of and percentage of voids and net volume of calcium silicate masonry units by sand filling; German version EN 772-9:1998— 4 стр.
91.100.15 Mineral. Including earth, sands, clay, slates, stones, etc. / Минеральные материалы и изделия. Включая землю, песок, глину, шифер, камень, кирпич и т.д.