DIN EN 772-20:2005-05 Methods of test for masonry units - Part 20: Determination of flatness of faces of masonry units; German version EN 772-20:2000 + A1:2005
2005DIN EN 772-20:2005-05 Methods of test for masonry units - Part 20: Determination of flatness of faces of masonry units; German version EN 772-20:2000 + A1:2005
2005DIN EN 772-20:2005 Methods of test for masonry units - Part 20: Determination of flatness of faces of masonry units; German version EN 772-20:2000 + A1:2005