Methods of test for masonry units - Part 21: Determination of water absorption of clay and calcium silicate masonry units by cold water absorption; German version EN 772-21:2011— 7 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.
