2005DIN EN 772-9:2005-05 Methods of test for masonry units - Part 9: Determination of volume and percentage of voids and net volume of clay and calcium silicate masonry units by sand filling; German version EN 772-9:1998 + A1:2005
2005DIN EN 772-9:2005 Methods of test for masonry units - Part 9: Determination of volume and percentage of voids and net volume of clay and calcium silicate masonry units by sand filling; German version EN 772-9:1998 + A1:2005