DIN EN 772-4:1998-10 Methods of test for masonry units - Part 4: Determination of real and bulk density and of total and open porosity for natural stone masonry units; German version EN 772-4:1998
1998DIN EN 772-4:1998-10 Methods of test for masonry units - Part 4: Determination of real and bulk density and of total and open porosity for natural stone masonry units; German version EN 772-4:1998
1998DIN EN 772-4:1998 Methods of test for masonry units - Part 4: Determination of real and bulk density and of total and open porosity for natural stone masonry units; German version EN 772-4:1998